Dual catalyst system for producing polyethylene with long chain branching for blow molding applications

ABSTRACT

Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm 3 , a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of η E /3η at an extensional rate of 0.1 sec −1  from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

BACKGROUND OF THE INVENTION

Polyolefins such as high density polyethylene (HDPE) homopolymer andcopolymer and linear low density polyethylene (LLDPE) copolymer can beproduced using various combinations of catalyst systems andpolymerization processes. Ziegler-Natta and chromium-based catalystsystems can, for example, produce ethylene polymers having goodextrusion processability, polymer melt strength in pipe and blow moldingapplications, and bubble stability in blown film applications, typicallydue to their broad molecular weight distribution (MWD).Metallocene-based catalyst systems can, for example, produce ethylenepolymers having excellent impact and toughness properties, but often atthe expense of poor extrusion processability, melt strength, and bubblestability.

In some end-uses, such as blow molding, it can be beneficial to have thetoughness properties of a metallocene-catalyzed copolymer, but withimproved processability, strain hardening, and melt strength.Accordingly, it is to these ends that the present invention is generallydirected.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

The present invention generally relates to ethylene polymers (e.g.,ethylene/α-olefin copolymers) characterized by a melt index of less thanor equal to about 1 g/10 min, a density in a range from about 0.94 toabout 0.965 g/cm³, a Mw in a range from about 100,000 to about 250,000g/mol, and a relaxation time from about 0.5 to about 3 seconds.

These ethylene polymers can be further characterized by an averagenumber of long chain branches (LCBs) per 1,000,000 total carbon atoms ofthe polymer in a molecular weight range of 300,000 to 900,000 g/mol thatis greater (by at least 50%, at least 100%, or at least 200%) than thatin a molecular weight range of 1,000,000 to 2,000,000 g/mol.Beneficially, most of the LCBs are present in lower molecular weightportions of the ethylene polymer, and not in the very high molecularweight fraction (often referred to as the high molecular weight tail ofthe molecular weight distribution). Additionally or alternatively, theseethylene polymers can be further characterized by an average number ofLCBs per 1,000,000 total carbon atoms of the polymer in a molecularweight range of 1,000,000 to 2,000,000 g/mol of less than or equal toabout 5 (effectively, little to no long chain branching in the highmolecular weight end), and a maximum ratio of η_(E)/3η at an extensionalrate of 0.1 sec⁻¹ in a range from about 1.2 to about 10 (the ratio ofextensional viscosity to 3 times the shear viscosity; for Newtonianfluids, the ratio is 1, and strain hardening results in ratios greaterthan 1).

Unexpectedly, there is substantially no long chain branching in the highmolecular weight fraction of these polymers that might adversely impactproperties of blow molded products. Beneficially, however, there is asignificant amount of long chain branching in lower molecular weightfractions of the polymer, such that polymer melt strength and parisonstability are maintained, as well as extrusion processability. Theethylene polymers disclosed herein can be used to produce variousarticles of manufacture, such as blow molded bottles and containers.

Another aspect of this invention is directed to a dual catalyst system,and in this aspect, the dual catalyst system can comprise catalystcomponent I comprising a single atom bridged or two atom bridgedmetallocene compound with two indenyl groups, catalyst component IIcomprising a single atom bridged metallocene compound with a fluorenylgroup and a cyclopentadienyl group, and with an alkenyl substituent onthe single atom bridge and/or on the cyclopentadienyl group, anactivator, and optionally, a co-catalyst.

In yet another aspect, an olefin polymerization process is provided, andin this aspect, the process can comprising contacting any catalystcomposition disclosed herein with an olefin monomer and an optionalolefin comonomer in a polymerization reactor system under polymerizationconditions to produce an olefin polymer. For instance, the olefinmonomer can be ethylene, and the olefin comonomer can be 1-butene,1-hexene, 1-octene, or a mixture thereof.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain aspects andembodiments may be directed to various feature combinations andsub-combinations described in the detailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 presents a plot of the molecular weight distributions of thepolymers of Examples 1-2 and Comparative Example 3.

FIG. 2 presents a plot of the short chain branch distributions acrossthe molecular weight distributions of the polymers of Example 1-2.

FIG. 3 presents a plot of the long chain branch distribution across themolecular weight distribution of the polymer of Example 1.

FIG. 4 presents a plot of the long chain branch distribution across themolecular weight distribution of the polymer of Example 2.

FIG. 5 presents a plot of the radius of gyration versus the molecularweight for a linear standard and the polymers of Examples 1-2.

FIG. 6 presents an extensional viscosity plot (extensional viscosityversus time) for the polymer of Example 1.

FIG. 7 presents an extensional viscosity plot (extensional viscosityversus time) for the polymer of Example 2.

FIG. 8 presents an extensional viscosity plot (extensional viscosityversus time) for the polymer of Comparative Example 4.

FIG. 9 presents a plot of the maximum ratio of η_(E)/3η at extensionalrates in the 0.03 to 10 sec⁻¹ range for the polymers of Examples 1-2.

FIG. 10 presents a dynamic rheology plot that compares the viscositiesof the polymers of Examples 1-2 to that of the polymer of ComparativeExample 3.

DEFINITIONS

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2nd Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

Herein, features of the subject matter are described such that, withinparticular aspects, a combination of different features can beenvisioned. For each and every aspect and/or feature disclosed herein,all combinations that do not detrimentally affect the designs,compositions, processes, and/or methods described herein arecontemplated with or without explicit description of the particularcombination. Additionally, unless explicitly recited otherwise, anyaspect and/or feature disclosed herein can be combined to describeinventive features consistent with the present disclosure.

While compositions and methods are described herein in terms of“comprising” various components or steps, the compositions and methodsalso can “consist essentially of” or “consist of” the various componentsor steps, unless stated otherwise. For example, a catalyst compositionconsistent with aspects of the present invention can comprise;alternatively, can consist essentially of; or alternatively, can consistof; catalyst component I, catalyst component II, an activator, and aco-catalyst.

The terms “a,” “an,” “the,” etc., are intended to include pluralalternatives, e.g., at least one, unless otherwise specified. Forinstance, the disclosure of “an activator-support” or “a metallocenecompound” is meant to encompass one, or mixtures or combinations of morethan one, activator-support or metallocene compound, respectively,unless otherwise specified.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, transition metals for Group 3-12 elements,and halogens or halides for Group 17 elements.

For any particular compound disclosed herein, the general structure orname presented is also intended to encompass all structural isomers,conformational isomers, and stereoisomers that can arise from aparticular set of substituents, unless indicated otherwise. Thus, ageneral reference to a compound includes all structural isomers unlessexplicitly indicated otherwise; e.g., a general reference to pentaneincludes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane, while ageneral reference to a butyl group includes an n-butyl group, asec-butyl group, an iso-butyl group, and a tert-butyl group.Additionally, the reference to a general structure or name encompassesall enantiomers, diastereomers, and other optical isomers whether inenantiomeric or racemic forms, as well as mixtures of stereoisomers, asthe context permits or requires. For any particular formula or name thatis presented, any general formula or name presented also encompasses allconformational isomers, regioisomers, and stereoisomers that can arisefrom a particular set of substituents.

The term “substituted” when used to describe a group, for example, whenreferring to a substituted analog of a particular group, is intended todescribe any non-hydrogen moiety that formally replaces a hydrogen inthat group, and is intended to be non-limiting. A group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen within that group.Unless otherwise specified, “substituted” is intended to be non-limitingand include inorganic substituents or organic substituents as understoodby one of ordinary skill in the art.

The term “hydrocarbon” whenever used in this specification and claimsrefers to a compound containing only carbon and hydrogen. Otheridentifiers can be utilized to indicate the presence of particulargroups in the hydrocarbon (e.g., halogenated hydrocarbon indicates thepresence of one or more halogen atoms replacing an equivalent number ofhydrogen atoms in the hydrocarbon). The term “hydrocarbyl group” is usedherein in accordance with the definition specified by IUPAC: a univalentgroup formed by removing a hydrogen atom from a hydrocarbon (that is, agroup containing only carbon and hydrogen). Non-limiting examples ofhydrocarbyl groups include alkyl, alkenyl, aryl, and aralkyl groups,amongst other groups.

The term “polymer” is used herein generically to include olefinhomopolymers, copolymers, terpolymers, and the like, as well as alloysand blends thereof. The term “polymer” also includes impact, block,graft, random, and alternating copolymers. A copolymer is derived froman olefin monomer and one olefin comonomer, while a terpolymer isderived from an olefin monomer and two olefin comonomers. Accordingly,“polymer” encompasses copolymers and terpolymers derived from any olefinmonomer and comonomer(s) disclosed herein. Similarly, the scope of theterm “polymerization” includes homopolymerization, copolymerization, andterpolymerization. Therefore, an ethylene polymer includes ethylenehomopolymers, ethylene copolymers (e.g., ethylene/α-olefin copolymers),ethylene terpolymers, and the like, as well as blends or mixturesthereof. Thus, an ethylene polymer encompasses polymers often referredto in the art as LLDPE (linear low density polyethylene) and HDPE (highdensity polyethylene). As an example, an olefin copolymer, such as anethylene copolymer, can be derived from ethylene and a comonomer, suchas 1-butene, 1-hexene, or 1-octene. If the monomer and comonomer wereethylene and 1-hexene, respectively, the resulting polymer can becategorized as an ethylene/1-hexene copolymer. The term “polymer” alsoincludes all possible geometrical configurations, unless statedotherwise, and such configurations can include isotactic, syndiotactic,and random symmetries. Moreover, unless stated otherwise, the term“polymer” also is meant to include all molecular weight polymers, and isinclusive of lower molecular weight polymers.

The term “co-catalyst” is used generally herein to refer to compoundssuch as aluminoxane compounds, organoboron or organoborate compounds,ionizing ionic compounds, organoaluminum compounds, organozinccompounds, organomagnesium compounds, organolithium compounds, and thelike, that can constitute one component of a catalyst composition, whenused, for example, in addition to an activator-support. The term“co-catalyst” is used regardless of the actual function of the compoundor any chemical mechanism by which the compound may operate.

The terms “chemically-treated solid oxide,” “treated solid oxidecompound,” and the like, are used herein to indicate a solid, inorganicoxide of relatively high porosity, which can exhibit Lewis acidic orBrønsted acidic behavior, and which has been treated with anelectron-withdrawing component, typically an anion, and which iscalcined. The electron-withdrawing component is typically anelectron-withdrawing anion source compound. Thus, the chemically-treatedsolid oxide can comprise a calcined contact product of at least onesolid oxide with at least one electron-withdrawing anion sourcecompound. Typically, the chemically-treated solid oxide comprises atleast one acidic solid oxide compound. The “activator-support” of thepresent invention can be a chemically-treated solid oxide. The terms“support” and “activator-support” are not used to imply these componentsare inert, and such components should not be construed as an inertcomponent of the catalyst composition. The term “activator,” as usedherein, refers generally to a substance that is capable of converting ametallocene component into a catalyst that can polymerize olefins, orconverting a contact product of a metallocene component and a componentthat provides an activatable ligand (e.g., an alkyl, a hydride) to themetallocene, when the metallocene compound does not already comprisesuch a ligand, into a catalyst that can polymerize olefins. This term isused regardless of the actual activating mechanism. Illustrativeactivators include activator-supports, aluminoxanes, organoboron ororganoborate compounds, ionizing ionic compounds, and the like.Aluminoxanes, organoboron or organoborate compounds, and ionizing ioniccompounds generally are referred to as activators if used in a catalystcomposition in which an activator-support is not present. If thecatalyst composition contains an activator-support, then thealuminoxane, organoboron or organoborate, and ionizing ionic materialsare typically referred to as co-catalysts.

The term “metallocene” as used herein describes compounds comprising atleast one η¹ to η⁵-cycloalkadienyl-type moiety, wherein η¹ toη⁵-cycloalkadienyl moieties include cyclopentadienyl ligands, indenylligands, fluorenyl ligands, and the like, including partially saturatedor substituted derivatives or analogs of any of these.

Possible substituents on these ligands can include H, therefore thisinvention comprises ligands such as tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, partially saturated indenyl,partially saturated fluorenyl, substituted partially saturated indenyl,substituted partially saturated fluorenyl, and the like. In somecontexts, the metallocene is referred to simply as the “catalyst,” inmuch the same way the term “co-catalyst” is used herein to refer to, forexample, an organoaluminum compound.

The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, do not depend upon the actual product or compositionresulting from the contact or reaction of the initial components of thedisclosed or claimed catalyst composition/mixture/system, the nature ofthe active catalytic site, or the fate of the co-catalyst, catalystcomponent I, catalyst component II, or the activator (e.g.,activator-support), after combining these components. Therefore, theterms “catalyst composition,” “catalyst mixture,” “catalyst system,” andthe like, encompass the initial starting components of the composition,as well as whatever product(s) may result from contacting these initialstarting components, and this is inclusive of both heterogeneous andhomogenous catalyst systems or compositions. The terms “catalystcomposition,” “catalyst mixture,” “catalyst system,” and the like, canbe used interchangeably throughout this disclosure.

The term “contact product” is used herein to describe compositionswherein the components are contacted together in any order, in anymanner, and for any length of time, unless otherwise specified. Forexample, the components can be contacted by blending or mixing. Further,contacting of any component can occur in the presence or absence of anyother component of the compositions described herein. Combiningadditional materials or components can be done by any suitable method.Further, the term “contact product” includes mixtures, blends,solutions, slurries, reaction products, and the like, or combinationsthereof. Although “contact product” can include reaction products, it isnot required for the respective components to react with one another.Similarly, the term “contacting” is used herein to refer to materialswhich can be blended, mixed, slurried, dissolved, reacted, treated, orotherwise combined in some other manner.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices, and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention.

Several types of ranges are disclosed in the present invention. When arange of any type is disclosed or claimed, the intent is to disclose orclaim individually each possible number that such a range couldreasonably encompass, including end points of the range as well as anysub-ranges and combinations of sub-ranges encompassed therein. Forexample, when a chemical moiety having a certain number of carbon atomsis disclosed or claimed, the intent is to disclose or claim individuallyevery possible number that such a range could encompass, consistent withthe disclosure herein. For example, the disclosure that a moiety is a C₁to C₁₈ hydrocarbyl group, or in alternative language, a hydrocarbylgroup having from 1 to 18 carbon atoms, as used herein, refers to amoiety that can have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, or 18 carbon atoms, as well as any range between these twonumbers (for example, a C₁ to C₈ hydrocarbyl group), and also includingany combination of ranges between these two numbers (for example, a C₂to C₄ and a C₁₂ to C₁₆ hydrocarbyl group).

Similarly, another representative example follows for the ratio of Mw/Mnof an ethylene polymer consistent with aspects of this invention. By adisclosure that the ratio of Mw/Mn can be in a range from about 5 toabout 15, the intent is to recite that the ratio of Mw/Mn can be anyratio in the range and, for example, can be equal to about 5, about 6,about 7, about 8, about 9, about 10, about 11, about 12, about 13, about14, or about 15. Additionally, the ratio of Mw/Mn can be within anyrange from about 5 to about 15 (for example, from about 6 to about 10),and this also includes any combination of ranges between about 5 andabout 15 (for example, the Mw/Mn ratio can be in a range from about 6 toabout 9, or from about 11 to about 14). Further, in all instances, where“about” a particular value is disclosed, then that value itself isdisclosed. Thus, the disclosure that the ratio of Mw/Mn can be fromabout 5 to about 15 also discloses a ratio of Mw/Mn from 5 to 15 (forexample, from 6 to 10), and this also includes any combination of rangesbetween 5 and 15 (for example, the Mw/Mn ratio can be in a range from 6to 9, or from 11 to 14). Likewise, all other ranges disclosed hereinshould be interpreted in a manner similar to these examples.

The term “about” means that amounts, sizes, formulations, parameters,and other quantities and characteristics are not and need not be exact,but can be approximate and/or larger or smaller, as desired, reflectingtolerances, conversion factors, rounding off, measurement errors, andthe like, and other factors known to those of skill in the art. Ingeneral, an amount, size, formulation, parameter or other quantity orcharacteristic is “about” or “approximate” whether or not expresslystated to be such. The term “about” also encompasses amounts that differdue to different equilibrium conditions for a composition resulting froma particular initial mixture. Whether or not modified by the term“about,” the claims include equivalents to the quantities. The term“about” can mean within 10% of the reported numerical value, preferablywithin 5% of the reported numerical value.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally to dual metalloceneethylene-based polymers having similar processability to chromium-basedpolymers, but with improved ESCR and toughness properties. Articlesproduced from these ethylene-based polymers can include blow moldedproducts, such as blow molded bottles.

Generally, metallocene-derived ethylene-based polymers with long chainbranches have those long chain branches concentrated in the highmolecular weight fraction of the polymer. Advantageously, the ethylenepolymers disclosed herein have substantially no long chain branching inthe high molecular weight fraction of the polymer; instead, significantamounts of long chain branching are present in lower molecular weightfractions of the polymer.

These ethylene polymers can be produced, for example, with a dualmetallocene catalyst system in a single reactor. It was found that usinga first metallocene catalyst that preferentially produces lowermolecular weight polyethylene with relatively high LCB content incombination with a second metallocene catalyst that preferentiallyproduces higher molecular weight, essentially linear polyethylene canresult in the unique combination of polymer properties described herein.

Ethylene Polymers

Generally, the polymers disclosed herein are ethylene-based polymers, orethylene polymers, encompassing homopolymers of ethylene as well ascopolymers, terpolymers, etc., of ethylene and at least one olefincomonomer. Comonomers that can be copolymerized with ethylene often canhave from 3 to 20 carbon atoms in their molecular chain. For example,typical comonomers can include, but are not limited to, propylene,1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and the like, orcombinations thereof. In an aspect, the olefin comonomer can comprise aC₃-C₁₈ olefin; alternatively, the olefin comonomer can comprise a C₃-C₁₀olefin; alternatively, the olefin comonomer can comprise a C₄-C₁₀olefin; alternatively, the olefin comonomer can comprise a C₃-C₁₀α-olefin; alternatively, the olefin comonomer can comprise a C₄-C₁₀α-olefin; alternatively, the olefin comonomer can comprise 1-butene,1-hexene, 1-octene, or any combination thereof, or alternatively, thecomonomer can comprise 1-hexene. Typically, the amount of the comonomer,based on the total weight of monomer (ethylene) and comonomer, can be ina range from about 0.01 to about 20 wt. %, from about 0.1 to about 10wt. %, from about 0.5 to about 15 wt. %, from about 0.5 to about 8 wt.%, or from about 1 to about 15 wt. %.

In one aspect, the ethylene polymer of this invention can comprise anethylene/α-olefin copolymer, while in another aspect, the ethylenepolymer can comprise an ethylene homopolymer, and in yet another aspect,the ethylene polymer of this invention can comprise an ethylene/α-olefincopolymer and an ethylene homopolymer. For example, the ethylene polymercan comprise an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, an ethylene/1-octene copolymer, an ethylene homopolymer, orany combination thereof, alternatively, an ethylene/1-butene copolymer,an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or anycombination thereof, or alternatively, an ethylene/1-hexene copolymer.

An illustrative and non-limiting example of an ethylene polymer (e.g.,comprising an ethylene copolymer) of the present invention can have amelt index of less than or equal to about 1 g/10 min, a density in arange from about 0.94 to about 0.965 g/cm³, a Mw in a range from about100,000 to about 250,000 g/mol, a relaxation time from about 0.5 toabout 3 sec, and an average number of long chain branches (LCBs) per1,000,000 total carbon atoms of the polymer in a molecular weight rangeof 300,000 to 900,000 g/mol that is greater (for instance, at least 50%greater, or at least 75% greater, or at least 100% greater, or at least150% greater, or at least 200% greater) than that in a molecular weightrange of 1,000,000 to 2,000,000 g/mol. Another illustrative andnon-limiting example of an ethylene polymer (e.g., comprising anethylene copolymer) of the present invention can have a melt index ofless than or equal to about 1 g/10 min, a density in a range from about0.94 to about 0.965 g/cm³, a Mw in a range from about 100,000 to about250,000 g/mol, a relaxation time from about 0.5 to about 3 sec, anaverage number of long chain branches (LCBs) per 1,000,000 total carbonatoms of the polymer in a molecular weight range of 1,000,000 to2,000,000 g/mol of less than or equal to about 5, and a maximum ratio ofη_(E)/3η at an extensional rate of 0.1 sec in a range from about 1.2 toabout 10. These ethylene polymers also can have any of the polymerproperties listed below and in any combination, unless indicatedotherwise.

The densities of ethylene-based polymers disclosed herein often aregreater than or equal to about 0.94 g/cm³, and less than or equal toabout 0.965 g/cm³. Yet, in particular aspects, the density can be in arange from about 0.942 to about 0.965 g/cm³, from about 0.94 to about0.96 g/cm³, from about 0.95 to about 0.965 g/cm³, from about 0.955 toabout 0.962 g/cm³, or from about 0.955 to about 0.96 g/cm³.

Ethylene polymers described herein often can have a melt index (MI) ofless than or equal to about 1 g/10 min, less than or equal to about 0.7g/10 min, or less than or equal to about 0.5 g/10 min. In furtheraspects, ethylene polymers described herein can have a melt index (MI)in a range from about 0.1 to about 0.7 g/10 min, from about 0.1 to about0.5 g/10 min, from about 0.2 to about 0.7 g/10 min, or from about 0.2 toabout 0.4 g/10 min.

While not being limited thereto, the ethylene polymer also can have ahigh load melt index (HLMI) in a range from about 10 to about 65 g/10min; alternatively, from about 35 to about 55 g/10 min; alternatively,from about 20 to about 60 g/10 min; or alternatively, from about 40 toabout 55 g/10 min.

The ratio of high load melt index (HLMI) to melt index (MI), referred toas the ratio of HLMI/MI, is not particularly limited, but typicallyranges from about 80 to about 220, from about 100 to about 200, fromabout 120 to about 170, or from about 130 to about 160. In this HLMI/MIratio, the melt index is not equal to zero.

In an aspect, ethylene polymers described herein can have a ratio ofMw/Mn, or the polydispersity index, in a range from about 5 to about 15,from about 6 to about 12, from about 6 to about 10, from about 7 toabout 13, or from about 7 to about 10. Additionally or alternatively,the ethylene polymer can have a ratio of Mz/Mw in a range from about 3.5to about 10, from about 4 to about 8, from about 4 to about 6, or fromabout 4.5 to about 5.5.

In an aspect, ethylene polymers described herein can have aweight-average molecular weight (Mw) in a range from about 125,000 toabout 250,000 g/mol, from about 100,000 to about 200,000 g/mol, fromabout 110,000 to about 190,000 g/mol, or from about 125,000 to about175,000 g/mol. Additionally or alternatively, the ethylene polymer canhave a number-average molecular weight (Mn) in a range from about 10,000to about 30,000 g/mol, from about 10,000 to about 25,000 g/mol, fromabout 15,000 to about 25,000 g/mol, or from about 15,000 to about 20,000g/mol. Additionally or alternatively, the ethylene polymer can have az-average molecular weight (Mz) in a range from about 500,000 to about2,000,000 g/mol, from about 600,000 to about 1,200,000 g/mol, from about650,000 to about 1,000,000 g/mol, or from about 700,000 to about 900,000g/mol.

Ethylene polymers consistent with certain aspects of the invention oftencan have a bimodal molecular weight distribution (as determined usinggel permeation chromatography (GPC) or other related analyticaltechnique). Often, in a bimodal molecular weight distribution, there isa valley between the peaks, and the peaks can be separated ordeconvoluted. Typically, a bimodal molecular weight distribution can becharacterized as having an identifiable high molecular weight component(or distribution) and an identifiable low molecular weight component (ordistribution). Illustrative unimodal MWD curves and bimodal MWD curvesare shown in U.S. Pat. No. 8,383,754, incorporated herein by referencein its entirety.

While not limited thereto, ethylene polymers described herein can have azero-shear viscosity at 190° C. in a range from about 1×10³ to about1×10⁸ Pa-sec, from about 1×10⁴ to about 1×10⁷ Pa-sec, or from about1×10⁴ to about 1×10⁶ Pa-sec. Moreover, these ethylene polymers can havea CY-a parameter from about 0.15 to about 0.45, from about 0.2 to about0.4, from about 0.22 to about 0.35, or from about 0.22 to about 0.32.Additionally or alternatively, these ethylene polymers can have arelatively short relaxation time given their relatively high molecularweight, with the relaxation time typically in a range from about 0.5 toabout 3 sec, such as from about 0.75 to about 2.5 sec, from about 1 toabout 2 sec, or from about 1 to about 1.5 sec. Additionally oralternatively, these ethylene polymers can be characterized by aviscosity at HLMI (eta @ HLMI or η@ HLMI) at 190° C. in a range fromabout 250 to about 800 Pa-sec, and more often, in a range from about 300to about 750, from about 300 to about 500, from about 300 to about 450,or from about 350 to about 450 Pa-sec. Additionally or alternatively,these ethylene polymers can have a viscosity at 100 sec⁻¹ (eta @ 100 orη @ 100) at 190° C. in a range from about 750 to about 1750, from about850 to about 1300, from about 1000 to about 1500, or from about 1000 toabout 1300 Pa-sec. Additionally or alternatively, these ethylenepolymers can have a ratio of η@ 0.1/η@ 100 (the viscosity at 0.1 sec⁻¹divided by the viscosity at 100 sec⁻¹) in a range from about 20 to about45, from about 20 to about 35, from about 22 to about 32, or from about25 to about 30. These rheological parameters are determined fromviscosity data measured at 190° C. and using the Carreau-Yasuda (CY)empirical model as described herein.

The average number of long chain branches (LCBs) per 1,000,000 totalcarbon atoms of the ethylene polymer in a molecular weight range of1,000,000 to 2,000,000 g/mol can be less than or equal to about 5 (thereis effectively no LCB in the high molecular weight fraction of thepolymer). All average numbers of LCBs disclosed herein arenumber-average numbers. In some aspects, the average number of LCBs per1,000,000 total carbon atoms of the polymer in the molecular weightrange of 1,000,000 to 2,000,000 g/mol can be less than or equal to about4, less than or equal to about 3.5, less than or equal to about 3, orless than or equal to about 1. In further aspects, the average number ofLCBs in this molecular weight range can be below the detection limit.

The average number of LCBs per 1,000,000 total carbon atoms of theethylene polymer in a molecular weight range of 300,000 to 900,000 g/molcan be greater (by any amount disclosed herein, e.g., at least 50%, atleast 75%, at least 100%, at least 150%, or at least 200%, and often upto 400-800%, or more) than the average number of LCBs per 1,000,000total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000g/mol. In some aspects, the average number of LCBs per 1,000,000 totalcarbon atoms of the ethylene polymer in a molecular weight range of300,000 to 900,000 g/mol can be at least 50% greater (or at least 75%greater, or at least 100% greater, or at least 150% greater, or at least200% greater, and often up to 400-800% greater) than that in a molecularweight range of 1,000,000 to 2,000,000 g/mol. As disclosed herein, allaverage numbers of LCBs are number-average numbers.

The average number of LCBs per 1,000,000 total carbon atoms of theethylene polymer in the molecular weight range of 300,000 to 900,000g/mol is not particularly limited, but often falls within a range fromabout 3 to about 15; alternatively, from about 4 to about 13;alternatively, from about 4 to about 10; alternatively, from about 5 toabout 9; or alternatively, from about 6 to about 8.

Likewise, the average number of LCBs per 1,000,000 total carbon atoms ofthe ethylene polymer in the molecular weight range of 400,000 to 600,000g/mol is not particularly limited, but often falls within a range fromabout 4 to about 15; alternatively, from about 5 to about 14;alternatively, from about 5 to about 12; alternatively, from about 7 toabout 10; or alternatively, from about 8 to about 9.

In the overall polymer (using the Janzen-Colby model), the ethylenepolymers typically have levels of long chain branches (LCBs) in a rangefrom about 4 to about 20 LCBs, from about 5 to about 15 LCBs, from about6 to about 14 LCBs, or from about 8 to about 12 LCBs, per 1,000,000total carbon atoms.

Unexpectedly, the ethylene polymers described herein can have a maximumratio of η_(E)/3η at an extensional rate of 0.1 sec⁻¹ in a range fromabout 1.2 to about 10. For Newtonian fluids, the ratio of extensionalviscosity to 3 times the shear viscosity is equal to 1, while strainhardening due to long chain branching can lead to ratios of greaterthan 1. In one aspect, the maximum ratio of η_(E)/3η at the extensionalrate of 0.1 sec⁻¹ can range from about 1.2 to about 10, or from about1.5 to about 8, while in another aspect, the maximum ratio can rangefrom about 1.5 to about 5, or from about 1.2 to about 4, and in yetanother aspect, the maximum ratio can range from about 1.2 to about 3,or from about 1.4 to about 3.5, and in still another aspect, the maximumratio can range from about 1.4 to about 3, or from about 1.5 to about2.5. These ratios of extensional viscosity to three times the shearviscosity are determined using a Sentmanat Extensional Rheometer (SER)at 150° C.

Additionally, while not being limited thereto, the ethylene polymer canbe characterized further by a maximum ratio of η_(E)/3η at anextensional rate of 0.03 sec⁻¹ in a range from about 1.2 to about 10;alternatively, from about 1.5 to about 8; alternatively, from about 2 toabout 7; alternatively, from about 2 to about 5; alternatively, fromabout 2.5 to about 4.5; or alternatively, from about 3 to about 4.

Moreover, the ethylene polymers (e.g., ethylene copolymers) typicallycan have a flat short chain branching distribution (flat SCBD; uniformcomonomer distribution). A flat SCBD can be characterized by a slope ofa plot of the number of short chain branches (SCBs) per 1000 totalcarbon atoms versus the logarithm of molecular weight of the ethylenepolymer (determined via linear regression over the range from D15 toD85) that is in a range from about −0.6 to about 0.6, and/or apercentage of data points deviating from the average short chain branchcontent by greater than 0.5 SCBs per 1000 total carbon atoms (determinedover the range from D15 to D85) that is less than or equal to about 20%,and/or a percentage of data points deviating from the average shortchain branch content by greater than 1 SCB per 1000 total carbon atoms(determined over the range from D15 to D85) that is less than or equalto about 10%. Polymers having a flat or uniform SCBD are disclosed, forexample, in U.S. Pat. Nos. 9,217,049 and 9,574,031, which areincorporated herein by reference in their entirety.

Aspects of this invention also are directed to the performance of theethylene polymer (e.g., an ethylene/1-hexene copolymer) onrepresentative blow molding equipment, as described herein below. Theethylene polymers can have a cycle time from about 13 to about 20, fromabout 14 to about 19, from about 15 to about 18, or from about 16 toabout 17 seconds; unexpectedly, these polymers can have cycle times thatare substantially the same as that of comparable chromium-based resins.Additionally or alternatively, ethylene polymers described herein canhave a part weight in a range from about 95 to about 115, from about 100to about 115, from about 95 to about 110, or from about 100 to about 110grams. Additionally or alternatively, ethylene polymers described hereincan have a layflat (top) in a range from about 5.2 to about 6, fromabout 5 to about 5.7, or from about 5.2 to about 5.7 inches.

Consistent with aspects of this disclosure, the ethylene polymers canhave a “bottle” environmental stress crack resistance (ESCR) of at least200 hours. Moreover, in some aspects, the ethylene polymers can have anESCR of at least 250 hours, at least 300 hours, at least 400 hours, orat least 500 hours, and often can range as high as 600 to 1000 hours.The “bottle” ESCR test is typically stopped after a certain number ofhours is reached, and given the long duration of the test, the upperlimit of ESCR (in hours) is generally not determined. The “bottle” ESCRtest is conducted in 10% Igepal at 140° F. (ASTM D2561), which is a muchmore stringent test than ESCR testing conducted using a 100% igepalsolution. Additionally or alternatively, the ethylene polymers can havea “bent strip” (ESCR) of at least 50 hours, such as at least 60 hours,at least 75 hours, at least 85 hours, or at least 100 hours, and oftencan range as high as 150 to 300 hours. As above, the “bent strip” ESCRtest is typically stopped after a certain number of hours is reached,and given the long duration of the test, the upper limit of ESCR (inhours) is generally not determined. The “bent strip” ESCR test isconducted in 10% Igepal at 50° C. for a 75 mil thickness (ASTM D1693).

In an aspect, the ethylene polymer can be a reactor product (e.g., asingle reactor product), for example, not a post-reactor blend of twopolymers, for instance, having different molecular weightcharacteristics. As one of skill in the art would readily recognize,physical blends of two different polymer resins can be made, but thisnecessitates additional processing and complexity not required for areactor product. Additionally, the ethylene polymer can further containany suitable additive, non-limiting examples of which include anantioxidant, an acid scavenger, an antiblock additive, a slip additive,a colorant, a filler, a polymer processing aid, a UV additive, and thelike, as well as any combination thereof.

Moreover, the ethylene polymers can be produced with a metallocenecatalyst system containing zirconium and hafnium, discussed furtherbelow. Ziegler-Natta, chromium, and titanium metallocene based catalystssystems are not required. Therefore, the ethylene polymer can contain nomeasurable amount of chromium or titanium (catalyst residue), i.e., lessthan 0.1 ppm by weight. In some aspects, the ethylene polymer cancontain, independently, less than 0.08 ppm, less than 0.05 ppm, or lessthan 0.03 ppm, of chromium and titanium.

Articles and Products

Articles of manufacture can be formed from, and/or can comprise, theolefin polymers (e.g., ethylene polymers) of this invention and,accordingly, are encompassed herein. For example, articles which cancomprise the polymers of this invention can include, but are not limitedto, an agricultural film, an automobile part, a bottle, a container forchemicals, a drum, a fiber or fabric, a food packaging film orcontainer, a food service article, a fuel tank, a geomembrane, ahousehold container, a liner, a molded product, a medical device ormaterial, an outdoor storage product (e.g., panels for walls of anoutdoor shed), outdoor play equipment (e.g., kayaks, bases forbasketball goals), a pipe, a sheet or tape, a toy, or a traffic barrier,and the like. Various processes can be employed to form these articles.Non-limiting examples of these processes include injection molding, blowmolding, rotational molding, film extrusion, sheet extrusion, profileextrusion, thermoforming, and the like. Additionally, additives andmodifiers often are added to these polymers in order to providebeneficial polymer processing or end-use product attributes. Suchprocesses and materials are described in Modern Plastics Encyclopedia,Mid-November 1995 Issue, Vol. 72, No. 12; and Film ExtrusionManual—Process, Materials, Properties, TAPPI Press, 1992; thedisclosures of which are incorporated herein by reference in theirentirety. In some aspects of this invention, an article of manufacturecan comprise any of olefin polymers (or ethylene polymers) describedherein, and the article of manufacture can be or can comprise a blowmolded product.

Also contemplated herein is a method for forming or preparing an articleof manufacture comprising any polymer disclosed herein. For instance, amethod can comprise (i) contacting a catalyst composition with an olefinmonomer (e.g., ethylene) and an optional olefin comonomer underpolymerization conditions in a polymerization reactor system to producean olefin polymer (e.g., an ethylene polymer), wherein the catalystcomposition can comprise catalyst component I, catalyst component II, anactivator (e.g., an activator-support comprising a solid oxide treatedwith an electron-withdrawing anion), and an optional co-catalyst (e.g.,an organoaluminum compound); and (ii) forming an article of manufacturecomprising the olefin polymer (or ethylene polymer). The forming stepcan comprise blending, melt processing, extruding, molding (e.g., blowmolding), or thermoforming, and the like, including combinationsthereof. Any suitable additive can be combined with the polymer in themelt processing step (extrusion step), such as antioxidants, acidscavengers, antiblock additives, slip additives, colorants, fillers,processing aids, UV inhibitors, and the like, as well as combinationsthereof.

Catalyst Systems and Polymerization Processes

In accordance with aspects of the present invention, the olefin polymer(e.g., the ethylene polymer) can be produced using a dual catalystsystem. In these aspects, catalyst component I can comprise any suitablesingle atom bridged or two atom bridged metallocene compound with twoindenyl groups, or any single atom bridged or two atom bridgedmetallocene compound disclosed herein with two indenyl groups. Catalystcomponent II can comprise any suitable single atom bridged metallocenecompound with a fluorenyl group and a cyclopentadienyl group, and withan alkenyl substituent on the single atom bridge and/or on thecyclopentadienyl group, or any single atom bridged metallocene compounddisclosed herein with a fluorenyl group and a cyclopentadienyl group,and with an alkenyl substituent on the single atom bridge and/or on thecyclopentadienyl group. The catalyst system also can comprise anysuitable activator or any activator disclosed herein, and optionally,any suitable co-catalyst or any co-catalyst disclosed herein.

Referring first to catalyst component II, which can comprise a singleatom bridged metallocene compound with a fluorenyl group and acyclopentadienyl group; an alkenyl substituent can be present on thesingle atom bridge, or on the cyclopentadienyl group, or both. In oneaspect, the fluorenyl group can be substituted, while in another aspect,the fluorenyl group can be unsubstituted. Additionally, the bridgedmetallocene compound of catalyst component II can contain zirconium,hafnium, or titanium, or alternatively, zirconium or hafnium. Further,the single atom bridge can be a single carbon atom or a single siliconatom, although not limited thereto. In some aspects, this bridging atomcan have two substituents independently selected from H or any C₁ to C₁₈hydrocarbyl group disclosed herein (e.g., one substituent, or bothsubstituents, can be a phenyl group). The alkenyl substituent on thecyclopentadienyl group (or on the bridging atom) can be any suitablealkenyl group, such as a C₃ to C₁₈ alkenyl group, or a C₃ to C₈ terminalalkenyl group.

Catalyst component II can comprise, in particular aspects of thisinvention, a bridged metallocene compound having formula (II):

Within formula (II), M, Cp, R^(X), R^(Y), E, and each X are independentelements of the bridged metallocene compound. Accordingly, the bridgedmetallocene compound having formula (II) can be described using anycombination of M, Cp, R^(X), R^(Y), E, and X disclosed herein.

In accordance with aspects of this invention, the metal in formula (II),M, can be Ti, Zr, or Hf. In one aspect, for instance, M can be Zr or Hf,while in another aspect, M can be Ti; alternatively, M can be Zr; oralternatively, M can be Hf.

Each X in formula (II) independently can be a monoanionic ligand. Insome aspects, suitable monoanionic ligands can include, but are notlimited to, H (hydride), BH₄, a halide, a C₁ to C₃₆ hydrocarbyl group, aC₁ to C₃₆ hydrocarboxy group, a C₁ to C₃₆ hydrocarbylaminyl group, a C₁to C₃₆ hydrocarbylsilyl group, a C₁ to C₃₆ hydrocarbylaminylsilyl group,—OBR¹ ₂, or —OSO₂R¹, wherein R¹ is a C₁ to C₃₆ hydrocarbyl group. It iscontemplated that each X can be either the same or a differentmonoanionic ligand. In addition to representative selections for each Xthat are disclosed herein, additional suitable hydrocarbyl groups,hydrocarboxy groups, hydrocarbylaminyl groups, hydrocarbylsilyl groups,and hydrocarbylaminylsilyl groups are disclosed, for example, in U.S.Pat. No. 9,758,600, incorporated herein by reference in its entirety.

In one aspect, each X independently can be H, BH₄, a halide (e.g., F,Cl, Br, etc.), a C₁ to C₁₈ hydrocarbyl group, a C₁ to C₁₈ hydrocarboxygroup, a C₁ to C₁₈ hydrocarbylaminyl group, a C₁ to C₁₈ hydrocarbylsilylgroup, or a C₁ to C₁₈ hydrocarbylaminylsilyl group. Alternatively, eachX independently can be H, BH₄, a halide, OBR¹ ₂, or OSO₂R¹, wherein R¹is a C₁ to C₁₈ hydrocarbyl group. In another aspect, each Xindependently can be H, BH₄, a halide, a C₁ to C₁₂ hydrocarbyl group, aC₁ to C₁₂ hydrocarboxy group, a C₁ to C₁₂ hydrocarbylaminyl group, a C₁to C₁₂ hydrocarbylsilyl group, a C₁ to C₁₂ hydrocarbylaminylsilyl group,OBR¹ ₂, or OSO₂R¹, wherein R¹ is a C₁ to C₁₂ hydrocarbyl group. Inanother aspect, each X independently can be H, BH₄, a halide, a C₁ toC₁₀ hydrocarbyl group, a C₁ to C₁₀ hydrocarboxy group, a C₁ to C₁₀hydrocarbylaminyl group, a C₁ to C₁₀ hydrocarbylsilyl group, a C₁ to C₁₀hydrocarbylaminylsilyl group, OBR¹ ₂, or OSO₂R¹, wherein R¹ is a C₁ toC₁₀ hydrocarbyl group. In yet another aspect, each X independently canbe H, BH₄, a halide, a C₁ to C₈ hydrocarbyl group, a C₁ to C₈hydrocarboxy group, a C₁ to C₈ hydrocarbylaminyl group, a C₁ to C₈hydrocarbylsilyl group, a C₁ to C₈ hydrocarbylaminylsilyl group, OBR¹ ₂,or OSO₂R¹, wherein R¹ is a C₁ to C₈ hydrocarbyl group. In still anotheraspect, each X independently can be a halide or a C₁ to C₁₈ hydrocarbylgroup. For example, each X can be C₁.

In one aspect, each X independently can be H, BH₄, a halide, or a C₁ toC₃₆ hydrocarbyl group, hydrocarboxy group, hydrocarbylaminyl group,hydrocarbylsilyl group, or hydrocarbylaminylsilyl group, while inanother aspect, each X independently can be H, BH₄, or a C₁ to C₁₈hydrocarboxy group, hydrocarbylaminyl group, hydrocarbylsilyl group, orhydrocarbylaminylsilyl group. In yet another aspect, each Xindependently can be a halide; alternatively, a C₁ to C₁₈ hydrocarbylgroup; alternatively, a C₁ to C₁₈ hydrocarboxy group; alternatively, aC₁ to C₁₈ hydrocarbylaminyl group; alternatively, a C₁ to C₁₈hydrocarbylsilyl group; or alternatively, a C₁ to C₁₈hydrocarbylaminylsilyl group. In still another aspect, each X can be H;alternatively, F; alternatively, C₁; alternatively, Br; alternatively,I; alternatively, BH₄; alternatively, a C₁ to C₁₈ hydrocarbyl group;alternatively, a C₁ to C₁₈ hydrocarboxy group; alternatively, a C₁ toC₁₈ hydrocarbylaminyl group; alternatively, a C₁ to C₁₈ hydrocarbylsilylgroup; or alternatively, a C₁ to C₁₈ hydrocarbylaminylsilyl group.

Each X independently can be, in some aspects, H, a halide, methyl,phenyl, benzyl, an alkoxy, an aryloxy, acetylacetonate, formate,acetate, stearate, oleate, benzoate, an alkylaminyl, a dialkylaminyl, atrihydrocarbylsilyl, or a hydrocarbylaminylsilyl; alternatively, H, ahalide, methyl, phenyl, or benzyl; alternatively, an alkoxy, an aryloxy,or acetylacetonate; alternatively, an alkylaminyl or a dialkylaminyl;alternatively, a trihydrocarbylsilyl or hydrocarbylaminylsilyl;alternatively, H or a halide; alternatively, methyl, phenyl, benzyl, analkoxy, an aryloxy, acetylacetonate, an alkylaminyl, or a dialkylaminyl;alternatively, H; alternatively, a halide; alternatively, methyl;alternatively, phenyl; alternatively, benzyl; alternatively, an alkoxy;alternatively, an aryloxy; alternatively, acetylacetonate;alternatively, an alkylaminyl; alternatively, a dialkylaminyl;alternatively, a trihydrocarbylsilyl; or alternatively, ahydrocarbylaminylsilyl. In these and other aspects, the alkoxy, aryloxy,alkylaminyl, dialkylaminyl, trihydrocarbylsilyl, andhydrocarbylaminylsilyl can be a C₁ to C₃₆, a C₁ to C₁₈, a C₁ to C₁₂, ora C₁ to C₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, and hydrocarbylaminylsilyl.

Moreover, each X independently can be, in certain aspects, a halide or aC₁ to C₁₈ hydrocarbyl group; alternatively, a halide or a C₁ to C₈hydrocarbyl group; alternatively, F, Cl, Br, I, methyl, benzyl, orphenyl; alternatively, C₁, methyl, benzyl, or phenyl; alternatively, aC₁ to C₁₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, or hydrocarbylaminylsilyl group; alternatively, aC₁ to C₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, or hydrocarbylaminylsilyl group; or alternatively,methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,decyl, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,nonenyl, decenyl, phenyl, tolyl, benzyl, naphthyl, trimethylsilyl,triisopropylsilyl, triphenylsilyl, or allyldimethylsilyl.

In formula (II), Cp can be a cyclopentadienyl group, optionally with analkenyl substituent. In some aspects, Cp can contain no additionalsubstituents, other than the alkenyl substituent. In other aspects, Cpcan be further substituted with one substituent, two substituents, andso forth. If present, each substituent on Cp independently can be H, ahalide, a C₁ to C₃₆ hydrocarbyl group, a C₁ to C₃₆ halogenatedhydrocarbyl group, a C₁ to C₃₆ hydrocarboxy group, or a C₁ to C₃₆hydrocarbylsilyl group. Importantly, each substituent on Cp can beeither the same or a different substituent group. Moreover, eachsubstituent can be at any position on the cyclopentadienyl ringstructure that conforms with the rules of chemical valence. In general,any substituent on Cp, independently, can be H or any halide, C₁ to C₃₆hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbyl group, C₁ to C₃₆hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl group describedherein. In addition to representative substituents that are disclosedherein, additional suitable hydrocarbyl groups, halogenated hydrocarbylgroups, hydrocarboxy groups, and hydrocarbylsilyl groups are disclosed,for example, in U.S. Pat. No. 9,758,600, incorporated herein byreference in its entirety.

In one aspect, for example, each substituent on Cp independently can bea C₁ to C₁₂ hydrocarbyl group or a C₁ to C₁₂ hydrocarbylsilyl group. Inanother aspect, each substituent on Cp independently can be a C₁ to C₈alkyl group or a C₃ to C₈ alkenyl group.

In yet another aspect, each substituent on Cp independently can be H,Cl, CF₃, a methyl group, an ethyl group, a propyl group, a butyl group,a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonylgroup, a decyl group, an ethenyl group, a propenyl group, a butenylgroup, a pentenyl group, a hexenyl group, a heptenyl group, an octenylgroup, a nonenyl group, a decenyl group, a phenyl group, a tolyl group,a benzyl group, a naphthyl group, a trimethylsilyl group, atriisopropylsilyl group, a triphenylsilyl group, or anallyldimethylsilyl group.

Similarly, R^(X) and R^(Y) in formula (II) independently can be H or anyhalide, C₁ to C₃₆ hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbylgroup, C₁ to C₃₆ hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl groupdisclosed herein. In one aspect, for example, R^(X) and R^(Y)independently can be H or a C₁ to C₁₂ hydrocarbyl group. In anotheraspect, R^(X) and R^(Y) independently can be a C₁ to C₁₀ hydrocarbylgroup or, alternatively, a C₁ to C₆ alkyl group. In yet another aspect,R^(X) and R^(Y) independently can be H, Cl, CF₃, a methyl group, anethyl group, a propyl group, a butyl group (e.g., t-Bu), a pentyl group,a hexyl group, a heptyl group, an octyl group, a nonyl group, a decylgroup, an ethenyl group, a propenyl group, a butenyl group, a pentenylgroup, a hexenyl group, a heptenyl group, an octenyl group, a nonenylgroup, a decenyl group, a phenyl group, a tolyl group, a benzyl group, anaphthyl group, a trimethylsilyl group, a triisopropylsilyl group, atriphenylsilyl group, or an allyldimethylsilyl group, and the like. Instill another aspect, R^(X) and R^(Y) independently can be a methylgroup, an ethyl group, a propyl group, a butyl group, a pentyl group, ahexyl group, a heptyl group, an octyl group, a nonyl group, a decylgroup, an ethenyl group, a propenyl group, a butenyl group, a pentenylgroup, a hexenyl group, a heptenyl group, an octenyl group, a nonenylgroup, a decenyl group, a phenyl group, a tolyl group, or a benzylgroup.

Bridging group E in formula (II) can be a bridging group having theformula >E^(A)R^(A)R^(B), wherein E^(A) can be C, Si, or Ge, and R^(A)and R^(B) independently can be H or a C₁ to C₁₈ hydrocarbyl group. Insome aspects of this invention, R^(A) and R^(B) independently can be aC₁ to C₁₂ hydrocarbyl group; alternatively, R^(A) and R^(B)independently can be a C₁ to C₈ hydrocarbyl group; alternatively, R^(A)and R^(B) independently can be a phenyl group, a C₁ to C₈ alkyl group,or a C₃ to C₈ alkenyl group; alternatively, R^(A) and R^(B)independently can be a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, an ethenyl group, a propenyl group,a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, acyclohexylphenyl group, a naphthyl group, a tolyl group, or a benzylgroup; or alternatively, R^(A) and R^(B) independently can be a methylgroup, an ethyl group, a propyl group, a butyl group, a pentyl group, ahexyl group, a propenyl group, a butenyl group, a pentenyl group, ahexenyl group, a phenyl group, or a benzyl group. In these and otheraspects, R^(A) and R^(B) can be either the same or different.

Illustrative and non-limiting examples of bridged metallocene compoundshaving formula (II) and/or suitable for use as catalyst component II caninclude the following compounds (Me=methyl, Ph=phenyl; t-Bu=tert-butyl):

and the like, as well as combinations thereof.

Catalyst component II is not limited solely to the bridged metallocenecompounds such as described above. Other suitable bridged metallocenecompounds are disclosed in U.S. Pat. Nos. 7,026,494, 7,041,617,7,226,886, 7,312,283, 7,517,939, and 7,619,047, which are incorporatedherein by reference in their entirety.

Referring now to catalyst component I, which can comprise, in particularaspects of this invention, a single atom bridged or two atom bridged(two atom chain) metallocene compound with two indenyl groups. In someaspects, the metallocene compound contains two unsubstituted indenylgroups. The bridge can be a single carbon atom; alternatively, a singlesilicon atom; alternatively, a two carbon atom bridge; or alternatively,a two silicon atom bridge. Independently, any bridging atom (or atoms)can have two substituents independently selected from H or a C₁ to C₁₈hydrocarbyl group, or from H or a C₁ to C₈ hydrocarbyl group;alternatively, two substituents independently selected from H or a C₁ toC₆ alkyl group; or alternatively, two substituents independentlyselected from a methyl group, an ethyl group, a propyl group, a butylgroup, a pentyl group, a hexyl group, a heptyl group, an octyl group, anonyl group, a decyl group, an ethenyl group, a propenyl group, abutenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, acyclohexylphenyl group, a naphthyl group, a tolyl group, or a benzylgroup. The two substituents can be either the same or different.

If the metallocene compound is a two carbon atom bridged metallocenecompound, the bridging group can have the formula—CR^(C)R^(D)—CR^(E)R^(F)—, wherein R^(C), R^(D), R^(E), and R^(F)independently can be H or any C₁ to C₁₈ hydrocarbyl group disclosedherein (and similarly for a two silicon atom bridge). For instance,R^(C), R^(D), R^(E), and R^(F) independently can be H or a C₁ to C₆alkyl group, or alternatively, H or a methyl group.

In other aspects, at least one indenyl group is substituted (thus, oneor both indenyl groups can be substituted). As above, the bridge can bea single carbon atom, a single silicon atom, a two carbon atom bridge,or a two silicon atom bridge, and further, each bridging atom (or atoms)can have two substituents independently selected from H or a C₁ to C₁₈hydrocarbyl group (e.g., a C₁ to C₆ alkyl group). Any substituent oneither indenyl group also can be independently selected from H or a C₁to C₁₈ hydrocarbyl group (e.g., a C₁ to C₆ alkyl group). While notlimited thereto, catalyst component I typically contains zirconium.

Illustrative and non-limiting examples of metallocene compounds suitablefor use as catalyst component I can include the following compounds:

and the like, as well a combination thereof.

Catalyst component I is not limited solely to the bridged metallocenecompounds such as described above. Other suitable metallocene compoundsare disclosed in U.S. Pat. Nos. 8,288,487 and 8,426,538, which areincorporated herein by reference in their entirety.

According to an aspect of this invention, the weight ratio of catalystcomponent I to catalyst component II in the catalyst composition can bein a range from about 25:1 to about 1:25, from about 10:1 to about 1:10,from about 8:1 to about 1:8, from about 5:1 to about 1:5, from about 3:1to about 1:3; from about 2:1 to about 1:2, from about 1.5:1 to about1:1.5, from about 1.25:1 to about 1:1.25, or from about 1.1:1 to about1:1.1. In another aspect, catalyst component II is the minor componentof the catalyst composition, and in such aspects, the weight ratio ofcatalyst component I to catalyst component II in the catalystcomposition can be in a range from about 1:1 to about 10:1, from about1.2:1 to about 5:1, from about 1.5:1 to about 4:1, or from about 1.5:1to about 2.5:1.

Additionally, the dual catalyst system contains an activator. Forexample, the catalyst system can contain an activator-support, analuminoxane compound, an organoboron or organoborate compound, anionizing ionic compound, and the like, or any combination thereof. Thecatalyst system can contain one or more than one activator.

In one aspect, the catalyst system can comprise an aluminoxane compound,an organoboron or organoborate compound, an ionizing ionic compound, andthe like, or a combination thereof. Examples of such activators aredisclosed in, for instance, U.S. Pat. Nos. 3,242,099, 4,794,096,4,808,561, 5,576,259, 5,807,938, 5,919,983, and 8,114,946, thedisclosures of which are incorporated herein by reference in theirentirety. In another aspect, the catalyst system can comprise analuminoxane compound. In yet another aspect, the catalyst system cancomprise an organoboron or organoborate compound. In still anotheraspect, the catalyst system can comprise an ionizing ionic compound.

In other aspects, the catalyst system can comprise an activator-support,for example, an activator-support comprising a solid oxide treated withan electron-withdrawing anion. Examples of such materials are disclosedin, for instance, U.S. Pat. Nos. 7,294,599, 7,601,665, 7,884,163,8,309,485, 8,623,973, and 9,023,959, which are incorporated herein byreference in their entirety. For instance, the activator-support cancomprise fluorided alumina, chlorided alumina, bromided alumina,sulfated alumina, fluorided silica-alumina, chlorided silica-alumina,bromided silica-alumina, sulfated silica-alumina, fluoridedsilica-zirconia, chlorided silica-zirconia, bromided silica-zirconia,sulfated silica-zirconia, fluorided silica-titania, fluorided-chloridedsilica-coated alumina, fluorided silica-coated alumina, sulfatedsilica-coated alumina, or phosphated silica-coated alumina, and thelike, as well as any combination thereof. In some aspects, theactivator-support can comprise a fluorided solid oxide and/or a sulfatedsolid oxide.

Various processes can be used to form activator-supports useful in thepresent invention. Methods of contacting the solid oxide with theelectron-withdrawing component, suitable electron withdrawing componentsand addition amounts, impregnation with metals or metal ions (e.g.,zinc, nickel, vanadium, titanium, silver, copper, gallium, tin,tungsten, molybdenum, zirconium, and the like, or combinations thereof),and various calcining procedures and conditions are disclosed in, forexample, U.S. Pat. Nos. 6,107,230, 6,165,929, 6,294,494, 6,300,271,6,316,553, 6,355,594, 6,376,415, 6,388,017, 6,391,816, 6,395,666,6,524,987, 6,548,441, 6,548,442, 6,576,583, 6,613,712, 6,632,894,6,667,274, 6,750,302, 7,294,599, 7,601,665, 7,884,163, and 8,309,485,which are incorporated herein by reference in their entirety. Othersuitable processes and procedures for preparing activator-supports(e.g., fluorided solid oxides, sulfated solid oxides, etc.) are wellknown to those of skill in the art.

The present invention can employ catalyst compositions containingcatalyst component I, catalyst component II, an activator (one or morethan one), and optionally, a co-catalyst. When present, the co-catalystcan include, but is not limited to, metal alkyl, or organometal,co-catalysts, with the metal encompassing boron, aluminum, zinc, and thelike. Optionally, the catalyst systems provided herein can comprise aco-catalyst, or a combination of co-catalysts. For instance, alkylboron, alkyl aluminum, and alkyl zinc compounds often can be used asco-catalysts in such catalyst systems. Representative boron compoundscan include, but are not limited to, tri-n-butyl borane,tripropylborane, triethylborane, and the like, and this includecombinations of two or more of these materials. While not being limitedthereto, representative aluminum compounds (e.g., organoaluminumcompounds) can include trimethylaluminum, triethylaluminum,tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum,tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride,diethylaluminum ethoxide, diethylaluminum chloride, and the like, aswell as any combination thereof. Exemplary zinc compounds (e.g.,organozinc compounds) that can be used as co-catalysts can include, butare not limited to, dimethylzinc, diethylzinc, dipropylzinc,dibutylzinc, dineopentylzinc, di(trimethylsilyl)zinc,di(triethylsilyl)zinc, di(triisoproplysilyl)zinc,di(triphenylsilyl)zinc, di(allyldimethylsilyl)zinc,di(trimethylsilylmethyl)zinc, and the like, or combinations thereof.Accordingly, in an aspect of this invention, the dual catalystcomposition can comprise catalyst component I, catalyst component II, anactivator-support, and an organoaluminum compound (and/or an organozinccompound).

In another aspect of the present invention, a catalyst composition isprovided which comprises catalyst component I, catalyst component II, anactivator-support, and an organoaluminum compound, wherein this catalystcomposition is substantially free of aluminoxanes, organoboron ororganoborate compounds, ionizing ionic compounds, and/or other similarmaterials; alternatively, substantially free of aluminoxanes;alternatively, substantially free or organoboron or organoboratecompounds; or alternatively, substantially free of ionizing ioniccompounds. In these aspects, the catalyst composition has catalystactivity, discussed herein, in the absence of these additionalmaterials. For example, a catalyst composition of the present inventioncan consist essentially of catalyst component I, catalyst component II,an activator-support, and an organoaluminum compound, wherein no othermaterials are present in the catalyst composition which wouldincrease/decrease the activity of the catalyst composition by more thanabout 10% from the catalyst activity of the catalyst composition in theabsence of said materials.

Catalyst compositions of the present invention generally have a catalystactivity greater than about 250 grams of ethylene polymer (homopolymerand/or copolymer, as the context requires) per gram of activator-supportper hour (abbreviated g/g/hr). In another aspect, the catalyst activitycan be greater than about 350, greater than about 450, or greater thanabout 550 g/g/hr. Yet, in another aspect, the catalyst activity can begreater than about 700 g/g/hr, greater than about 1000 g/g/hr, orgreater than about 2000 g/g/hr, and often as high as 3500-6000 g/g/hr.Illustrative and non-limiting ranges for the catalyst activity includefrom about 500 to about 5000, from about 750 to about 4000, or fromabout 1000 to about 3500 g/g/hr, and the like. These activities aremeasured under slurry polymerization conditions, with atriisobutylaluminum co-catalyst, using isobutane as the diluent, at apolymerization temperature of about 95° C. and a reactor pressure ofabout 590 psig. Moreover, in some aspects, the activator-support cancomprise sulfated alumina, fluorided silica-alumina, or fluoridedsilica-coated alumina, although not limited thereto.

This invention further encompasses methods of making these catalystcompositions, such as, for example, contacting the respective catalystcomponents in any order or sequence. In one aspect, for example, thecatalyst composition can be produced by a process comprising contacting,in any order, catalyst component I, catalyst component II, and theactivator, while in another aspect, the catalyst composition can beproduced by a process comprising contacting, in any order, catalystcomponent I, catalyst component II, the activator, and the co-catalyst.

Olefin polymers (e.g., ethylene polymers) can be produced from thedisclosed catalyst systems using any suitable olefin polymerizationprocess using various types of polymerization reactors, polymerizationreactor systems, and polymerization reaction conditions. One such olefinpolymerization process for polymerizing olefins in the presence of acatalyst composition of the present invention can comprise contactingthe catalyst composition with an olefin monomer and optionally an olefincomonomer (one or more) in a polymerization reactor system underpolymerization conditions to produce an olefin polymer, wherein thecatalyst composition can comprise, as disclosed herein, catalystcomponent I, catalyst component II, an activator, and an optionalco-catalyst. This invention also encompasses any olefin polymers (e.g.,ethylene polymers) produced by any of the polymerization processesdisclosed herein.

As used herein, a “polymerization reactor” includes any polymerizationreactor capable of polymerizing (inclusive of oligomerizing) olefinmonomers and comonomers (one or more than one comonomer) to producehomopolymers, copolymers, terpolymers, and the like. The various typesof polymerization reactors include those that can be referred to as abatch reactor, slurry reactor, gas-phase reactor, solution reactor, highpressure reactor, tubular reactor, autoclave reactor, and the like, orcombinations thereof; or alternatively, the polymerization reactorsystem can comprise a slurry reactor, a gas-phase reactor, a solutionreactor, or a combination thereof. The polymerization conditions for thevarious reactor types are well known to those of skill in the art. Gasphase reactors can comprise fluidized bed reactors or staged horizontalreactors. Slurry reactors can comprise vertical or horizontal loops.High pressure reactors can comprise autoclave or tubular reactors.Reactor types can include batch or continuous processes. Continuousprocesses can use intermittent or continuous product discharge.Polymerization reactor systems and processes also can include partial orfull direct recycle of unreacted monomer, unreacted comonomer, and/ordiluent.

A polymerization reactor system can comprise a single reactor ormultiple reactors (2 reactors, more than 2 reactors, etc.) of the sameor different type. For instance, the polymerization reactor system cancomprise a slurry reactor, a gas-phase reactor, a solution reactor, or acombination of two or more of these reactors. Production of polymers inmultiple reactors can include several stages in at least two separatepolymerization reactors interconnected by a transfer device making itpossible to transfer the polymers resulting from the firstpolymerization reactor into the second reactor. The desiredpolymerization conditions in one of the reactors can be different fromthe operating conditions of the other reactor(s). Alternatively,polymerization in multiple reactors can include the manual transfer ofpolymer from one reactor to subsequent reactors for continuedpolymerization. Multiple reactor systems can include any combinationincluding, but not limited to, multiple loop reactors, multiple gasphase reactors, a combination of loop and gas phase reactors, multiplehigh pressure reactors, or a combination of high pressure with loopand/or gas phase reactors. The multiple reactors can be operated inseries, in parallel, or both. Accordingly, the present inventionencompasses polymerization reactor systems comprising a single reactor,comprising two reactors, and comprising more than two reactors. Thepolymerization reactor system can comprise a slurry reactor, a gas-phasereactor, a solution reactor, in certain aspects of this invention, aswell as multi-reactor combinations thereof.

According to one aspect, the polymerization reactor system can compriseat least one loop slurry reactor comprising vertical or horizontalloops. Monomer, diluent, catalyst, and comonomer can be continuously fedto a loop reactor where polymerization occurs. Generally, continuousprocesses can comprise the continuous introduction of monomer/comonomer,a catalyst, and a diluent into a polymerization reactor and thecontinuous removal from this reactor of a suspension comprising polymerparticles and the diluent. Reactor effluent can be flashed to remove thesolid polymer from the liquids that comprise the diluent, monomer and/orcomonomer. Various technologies can be used for this separation stepincluding, but not limited to, flashing that can include any combinationof heat addition and pressure reduction, separation by cyclonic actionin either a cyclone or hydrocyclone, or separation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess) is disclosed, for example, in U.S. Pat. Nos. 3,248,179,4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, 6,833,415, and8,822,608, each of which is incorporated herein by reference in itsentirety.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under reaction conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used.

According to yet another aspect, the polymerization reactor system cancomprise at least one gas phase reactor (e.g., a fluidized bed reactor).Such reactor systems can employ a continuous recycle stream containingone or more monomers continuously cycled through a fluidized bed in thepresence of the catalyst under polymerization conditions. A recyclestream can be withdrawn from the fluidized bed and recycled back intothe reactor. Simultaneously, polymer product can be withdrawn from thereactor and new or fresh monomer can be added to replace the polymerizedmonomer. Such gas phase reactors can comprise a process for multi-stepgas-phase polymerization of olefins, in which olefins are polymerized inthe gaseous phase in at least two independent gas-phase polymerizationzones while feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone. Representative gasphase reactors are disclosed in U.S. Pat. Nos. 5,352,749, 4,588,790,5,436,304, 7,531,606, and 7,598,327, each of which is incorporated byreference in its entirety herein.

According to still another aspect, the polymerization reactor system cancomprise a high pressure polymerization reactor, e.g., can comprise atubular reactor or an autoclave reactor. Tubular reactors can haveseveral zones where fresh monomer, initiators, or catalysts are added.Monomer can be entrained in an inert gaseous stream and introduced atone zone of the reactor. Initiators, catalysts, and/or catalystcomponents can be entrained in a gaseous stream and introduced atanother zone of the reactor. The gas streams can be intermixed forpolymerization. Heat and pressure can be employed appropriately toobtain optimal polymerization reaction conditions.

According to yet another aspect, the polymerization reactor system cancomprise a solution polymerization reactor wherein the monomer/comonomerare contacted with the catalyst composition by suitable stirring orother means. A carrier comprising an inert organic diluent or excessmonomer can be employed. If desired, the monomer/comonomer can bebrought in the vapor phase into contact with the catalytic reactionproduct, in the presence or absence of liquid material. Thepolymerization zone can be maintained at temperatures and pressures thatwill result in the formation of a solution of the polymer in a reactionmedium. Agitation can be employed to obtain better temperature controland to maintain uniform polymerization mixtures throughout thepolymerization zone. Adequate means are utilized for dissipating theexothermic heat of polymerization.

The polymerization reactor system can further comprise any combinationof at least one raw material feed system, at least one feed system forcatalyst or catalyst components, and/or at least one polymer recoverysystem. Suitable reactor systems can further comprise systems forfeedstock purification, catalyst storage and preparation, extrusion,reactor cooling, polymer recovery, fractionation, recycle, storage,loadout, laboratory analysis, and process control. Depending upon thedesired properties of the olefin polymer, hydrogen can be added to thepolymerization reactor as needed (e.g., continuously, pulsed, etc.).

Polymerization conditions that can be controlled for efficiency and toprovide desired polymer properties can include temperature, pressure,and the concentrations of various reactants. Polymerization temperaturecan affect catalyst productivity, polymer molecular weight, andmolecular weight distribution. Various polymerization conditions can beheld substantially constant, for example, for the production of aparticular grade of the olefin polymer (or ethylene polymer). A suitablepolymerization temperature can be any temperature below thede-polymerization temperature according to the Gibbs Free energyequation. Typically, this includes from about 60° C. to about 280° C.,for example, or from about 60° C. to about 120° C., depending upon thetype of polymerization reactor(s). In some reactor systems, thepolymerization temperature generally can be within a range from about70° C. to about 100° C., or from about 75° C. to about 95° C.

Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor is typically less than 1000 psig (6.9 MPa). Pressure forgas phase polymerization is usually at about 200 to 500 psig (1.4 MPa to3.4 MPa). High pressure polymerization in tubular or autoclave reactorsis generally run at about 20,000 to 75,000 psig (138 to 517 MPa).Polymerization reactors can also be operated in a supercritical regionoccurring at generally higher temperatures and pressures. Operationabove the critical point of a pressure/temperature diagram(supercritical phase) can offer advantages to the polymerizationreaction process.

Olefin monomers that can be employed with catalyst compositions andpolymerization processes of this invention typically can include olefincompounds having from 2 to 30 carbon atoms per molecule and having atleast one olefinic double bond, such as ethylene or propylene. In anaspect, the olefin monomer can comprise a C₂-C₂₀ olefin; alternatively,a C₂-C₂₀ alpha-olefin; alternatively, a C₂-C₁₀ olefin; alternatively, aC₂-C₁₀ alpha-olefin; alternatively, the olefin monomer can compriseethylene; or alternatively, the olefin monomer can comprise propylene(e.g., to produce a polypropylene homopolymer or a propylene-basedcopolymer).

When a copolymer (or alternatively, a terpolymer) is desired, the olefinmonomer and the olefin comonomer independently can comprise, forexample, a C₂-C₂₀ alpha-olefin. In some aspects, the olefin monomer cancomprise ethylene or propylene, which is copolymerized with at least onecomonomer (e.g., a C₂-C₂₀ alpha-olefin, a C₃-C₂₀ alpha-olefin, etc.).According to one aspect of this invention, the olefin monomer used inthe polymerization process can comprise ethylene. In this aspect, thecomonomer can comprise a C₃-C₁₀ alpha-olefin; alternatively, thecomonomer can comprise 1-butene, 1-pentene, 1-hexene, 1-octene,1-decene, styrene, or any combination thereof, alternatively, thecomonomer can comprise 1-butene, 1-hexene, 1-octene, or any combinationthereof, alternatively, the comonomer can comprise 1-butene;alternatively, the comonomer can comprise 1-hexene; or alternatively,the comonomer can comprise 1-octene.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, maysuggest themselves to one of ordinary skill in the art without departingfrom the spirit of the present invention or the scope of the appendedclaims.

Melt index (MI, g/10 min) was determined in accordance with ASTM D1238at 190° C. with a 2,160 gram weight, and high load melt index (HLMI,g/10 min) was determined in accordance with ASTM D1238 at 190° C. with a21,600 gram weight. Density was determined in grams per cubic centimeter(g/cm³) on a compression molded sample, cooled at 15° C. per hour, andconditioned for 40 hours at room temperature in accordance with ASTMD1505 and ASTM D4703.

Molecular weights and molecular weight distributions were obtained usinga PL-GPC 220 (Polymer Labs, an Agilent Company) system equipped with aIR4 detector (Polymer Char, Spain) and three Styragel HMW-6E GPC columns(Waters, Mass.) running at 145° C. The flow rate of the mobile phase1,2,4-trichlorobenzene (TCB) containing 0.5 g/L2,6-di-t-butyl-4-methylphenol (BHT) was set at 1 mL/min, and polymersolution concentrations were in the range of 1.0-1.5 mg/mL, depending onthe molecular weight. Sample preparation was conducted at 150° C. fornominally 4 hr with occasional and gentle agitation, before thesolutions were transferred to sample vials for injection. An injectionvolume of about 400 μL was used. The integral calibration method wasused to deduce molecular weights and molecular weight distributionsusing a Chevron Phillips Chemical Company's HDPE polyethylene resin,MARLEX® BHB5003, as the standard. The integral table of the standard waspre-determined in a separate experiment with SEC-MALS. Mn is thenumber-average molecular weight, Mw is the weight-average molecularweight, Mz is the z-average molecular weight, and Mp is the peakmolecular weight (location, in molecular weight, of the highest point ofthe molecular weight distribution curve).

Melt rheological characterizations were performed as follows.Small-strain (less than 10%) oscillatory shear measurements wereperformed on an Anton Paar MCR rheometer using parallel-plate geometry.All rheological tests were performed at 190° C. The complex viscosity|η*| versus frequency (ω) data were then curve fitted using the modifiedthree parameter Carreau-Yasuda (CY) empirical model to obtain the zeroshear viscosity—η₀, characteristic viscous relaxation time—τ_(η), andthe breadth parameter—a (CY-a parameter). The simplified Carreau-Yasuda(CY) empirical model is as follows.

${{{\eta^{*}(\omega)}} = \frac{\eta_{0}}{\left\lbrack {1 + \left( {\tau_{\eta}\omega} \right)^{a}} \right\rbrack^{{({1 - n})}\text{/}a}}},$

wherein: |η*(ω)|=magnitude of complex shear viscosity;

-   -   η₀=zero shear viscosity;    -   τ_(η)=viscous relaxation time (Tau(η));    -   a=“breadth” parameter (CY-a parameter);    -   n=fixes the final power law slope, fixed at 2/11; and    -   ω=angular frequency of oscillatory shearing deformation.

Details of the significance and interpretation of the CY model andderived parameters can be found in: C. A. Hieber and H. H. Chiang,Rheol. Acta, 28, 321 (1989); C. A. Hieber and H. H. Chiang, Polym. Eng.Sci., 32, 931 (1992); and R. B. Bird, R. C. Armstrong and O. Hasseger,Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2nd Edition,John Wiley & Sons (1987); each of which is incorporated herein byreference in its entirety. A creep adjustment was used to extend the lowfrequency range of rheological characterization to 10⁻⁴ sec⁻¹, asdescribed in U.S. Pat. No. 9,169,337, incorporated herein by referencesin its entirety.

Polymer viscosities at 0.1 sec⁻¹, at 100 sec⁻¹, and at HLMI weredetermined from the Carreau-Yasuda model at 190° C. with creepadjustment, described hereinabove.

The long chain branches (LCBs) per 1,000,000 total carbon atoms of theoverall polymer were calculated using the method of Janzen and Colby (J.Mol. Struct., 485/486, 569-584 (1999), incorporated herein by referencein its entirety), from values of zero shear viscosity, η_(o) (determinedfrom the Carreau-Yasuda model with creep adjustment, describedhereinabove) and measured values of Mw obtained using a Dawn EOSmultiangle light scattering detector (Wyatt).

LCB content and LCB distribution were determined using the methodestablished by Yu, et al (Yu, DesLauriers, Rohlfing, Polymer, 2015, 46,5165-5192, incorporated herein by reference in its entirety). Briefly,in the SEC-MALS system, a DAWN EOS photometer (Wyatt Technology, SantaBarbara, Calif.) was attached to a Waters 150-CV plus GPC system(Milford, Mass.) or a PL-210 GPC system (Polymer Labs, an Agilentcompany) through ahot-transfer line controlled at 145° C. Degassedmobile phase 1,2,4-trichlorobenzene (TCB) containing 0.5 wt % of BHT(butylated hydroxytoluene) was pumped through an inline filter beforepassing through a SEC column bank. Polymer solutions injected to thesystem were brought downstream to the columns by the mobile phase forfractionation. The fractionated polymers first eluted through the MALSphotometer where light scattering signals were recorded before passingthrough the differential refractive index detector (DRI) or an IR4detector (Polymer Characterization SA, Spain) where their concentrationswere quantified.

The DAWN EOS system was calibrated with neat toluene at room temperatureto convert the measured voltage to intensity of scattered light. Duringthe calibration, toluene was filtered with a 0.02 um filter (Whatman)and directly passed through the flowcell of the EOS system. At roomtemperature, the Rayleigh ratio is given by 1.406×10⁻⁵ cm⁻¹. A narrowpolystyrene (PS) standard (American Polymer Standards) with MW of 30,000g/mol at a concentration about 5˜10 mg/mL in TCB was employed tonormalize the system at 145° C. At the given chromatographic conditions,the radius of gyration (R_(g)) of the polystyrene (PS) was estimated tobe 5.6 nm. The differential refractive index detector (DRI) wascalibrated with a known quantity of PE standard. By averaging the totalchromatographic areas of recorded chromatograms for at least fiveinjections, the DRI constant (α_(RI)) was obtained using the equationbelow (equation 1):

$\begin{matrix}{\alpha_{RI} = {\left( \frac{dn}{dc} \right)c\text{/}I_{RI}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

where I_(RI) is the DRI detector intensity, c is the polymerconcentration, and dn/dc is the refractive index increment of PE in TCBat the measuring temperature.

At a flow rate set at 0.7 mL/min, the mobile phase was eluted throughthree (3) 7.5 mm×300 mm 20 μm mixed A columns (Polymer Labs, an Agilentcompany). PE solutions with nominal concentrations of 1.5 mg/mL wereprepared at 150° C. for 4 h. At each chromatographic slice, both theabsolute molecular weight (M) and the root mean square (RMS) radius,aka, radius of gyration, R_(g), were obtained from the Debye plots. Thelinear PE control employed was CPChem Marlex™ HiD9640, a high-density PEwith broad MWD. The refractive index increment dn/dc used in this studywas 0.097 mL/g for PE dissolved in TCB at 135° C.

The Zimm-Stockmayer approach (Zimm, Stockmayer, J. Chem. Phys. 1949, 17,1301, incorporated herein by reference in its entirety) was employed todetermine the amount of LCB in the polyethylene resins. In SEC-MALS,both M and R_(g) were measured simultaneously at each slice of achromatogram. At the same molecular weight, R_(g) of a branched polymeris smaller than that of a linear polymer. The branching index (g_(M))factor is defined as the ratio of the mean square radius of gyration ofthe branched polymer to that of the linear one at the same molecularweight using equation 2,

$\begin{matrix}{g_{M} \equiv \left( \frac{\left\langle R_{g}^{2} \right\rangle_{b}}{\left\langle R_{g}^{2} \right\rangle_{l}} \right)_{M}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

where the subscripts b and l represent the branched and linear polymer,respectively.

The weight-average LCB per molecule (B_(3w)) was calculated usingEquation 3 using an in-house software,

$\begin{matrix}{g_{M} = {\frac{6}{B_{3w}}\left\{ {{\frac{1}{2}\left( \frac{2 + B_{3w}}{B_{3w}} \right)^{1\text{/}2}{\ln\left\lbrack \frac{\left( {2 + B_{3w}} \right)^{1\text{/}2} + \left( B_{3w} \right)^{1\text{/}2}}{\left( {2 + B_{3w}} \right)^{1\text{/}2} - \left( B_{3w} \right)^{1\text{/}2}} \right\rbrack}} - 1} \right\}}} & (3)\end{matrix}$

LCB frequency (λ_(M) _(i) , number of LCB per 1,000 total carbons) wascalculated using equation 4 using the B_(3w) value obtained fromequation 3,

λ_(M) _(i) =1,000×M ₀ ×B _(3w) /M _(i)  (4)

where M₀ is the unit molecular weight of polyethylene, M_(i) is themolecular weight of the i^(th) slice.

Since the presence of SCB in a polymer can affect its R_(g)-MWrelationship, the SCB effect was corrected before using equation 3 and 4for LCB and LCB distribution calculation for PE copolymers. To correctthe SCB effect on the branching index across the MWD, two relationshipsare needed: one is the relationship between the branching-indexcorrection factor (Δg_(M)) and the SCB content (x_(SCB)), and the otheris the relationship between SCB content and molecular weight, both ofwhich were determined experimentally. Mathematically, the product ofthese two relationships gives the branching index correction factor(Δg_(M)) as a function of MW, as shown in equation 5,

$\begin{matrix}{\frac{d\left( {\Delta\; g_{M}} \right)}{d(M)} = {\frac{d\left( x_{SCB} \right)}{d(M)} \times \frac{d\left( {\Delta\; g_{M}} \right)}{d\left( x_{SCB} \right)}}} & (5)\end{matrix}$

where x_(SCB) is the SCB content (i.e., number of SCB per 1,000 totalcarbons) of the copolymer in question.

To establish the relationship between Δg_(M) and x_(SCB), PE standardsthat met the following criteria were used: the standards containessentially no LCB and have flat SCB distribution and known SCBcontents. At least five SCB standards were used for the SCB effectcorrection. The SCB content for these SCB standards ranged from 0 to 34SCB/1,000 total carbon atoms.

Short chain branch content and short chain branching distribution (SCBD)across the molecular weight distribution were determined via anIR5-detected GPC system (IR5-GPC) using the method established by Yu (Y.Yu, Macromolecular Symposium, 2020, 390, 1900014), wherein the GPCsystem was a PL220 GPC/SEC system (Polymer Labs, an Agilent company)equipped with three Styragel HMW-6E columns (Waters, Mass.) for polymerseparation. A thermoelectric-cooled IR5 MCT detector (IR5) (PolymerCharacterisation SA, Spain) was connected to the GPC columns via ahot-transfer line. Chromatographic data was obtained from two outputports of the IR5 detector. First, the analog signal goes from the analogoutput port to a digitizer before connecting to Computer “A” formolecular weight determinations via the Cirrus software (Polymer Labs,now an Agilent Company) and the integral calibration method using a HDPEMarlex™ BHB5003 resin (Chevron Phillips Chemical) as the molecularweight standard. The digital signals, on the other hand, go via a USBcable directly to Computer “B” where they are collected by a LabViewdata collection software provided by Polymer Char. Chromatographicconditions were set as follows: column oven temperature of 145° C.;flowrate of 1 mL/min; injection volume of 0.4 mL; and polymerconcentration of about 2 mg/mL, depending on sample molecular weight.The temperatures for both the hot-transfer line and IR5 detector samplecell were set at 150° C., while the temperature of the electronics ofthe IR5 detector was set at 60° C. Short chain branching content wasdetermined via an in-house method using the intensity ratio of CH₃(I_(CH3)) to CH₂ (I_(CH2)) coupled with a calibration curve. Thecalibration curve was a plot of SCB content (x_(SCB)) as a function ofthe intensity ratio of I_(CH3)/I_(CH2). To obtain a calibration curve, agroup of polyethylene resins (no less than 5) of SCB level ranging fromzero to ca. 32 SCB/1,000 total carbons (SCB Standards) were used. Allthese SCB Standards have known SCB levels and flat SCBD profilespre-determined separately by NMR and the solvent-gradient fractionationcoupled with NMR (SGF-NMR) methods. Using SCB calibration curves thusestablished, profiles of short chain branching distribution across themolecular weight distribution were obtained for resins fractionated bythe IR5-GPC system under exactly the same chromatographic conditions asfor these SCB standards. A relationship between the intensity ratio andthe elution volume was converted into SCB distribution as a function ofMWD using a predetermined SCB calibration curve (i.e., intensity ratioof I_(CH3)/I_(CH2) vs. SCB content) and MW calibration curve (i.e.,molecular weight vs. elution time) to convert the intensity ratio ofI_(CH3)/I_(CH2) and the elution time into SCB content and the molecularweight, respectively.

Extensional viscosity was measured on a rotational rheometer (PhysicaMCR-500, Anton Paar) using the extensional viscosity fixture, aSentimanat Extensional Rheometer (model SER-3 universal testingplatform, Xpansion Instruments). The SER attachment makes it possible toeasily measure the transient extensional viscosity as a function oftime.

Test samples were prepared via compression molding at 182° C. Thepellets samples were allowed to melt at a relatively low pressure for 1min and then subjected to a high molding pressure for additional 2 min.Then, the hot press was turned off for slow cooling. The cooled plaquewas retrieved from the press on the following day. Rectangular stripswith dimensions of 12.77×18 mm were cut out of the molded plaque, andthe thickness of the sample was measured.

The SER testing platform has two drums that rotate in the opposingdirection (M. L. Sentmanat, “Miniature universal testing platform: fromextensional melt rheology to solid-state deformation behavior,” Rheol.Acta 43, 657 (2004); M. L. Sentmanat, B. N. Wang, G. H. McKinley,“Measuring the transient extensional rheology of polyethylene meltsusing the SER universal testing platform,” J. Rheol. 49, 585 (2005);both incorporated herein by reference in their entirety). Therectangular samples were tested by clipping onto the two posts of thefixture, then closing the oven to heat to 150° C., where it was annealedat 150° C. for 30 sec to allow the temperature to reach equilibrium. Thesample was then stretched at constant Hencky strain rates {dot over(ε)}_(H) between 0.03 and 25 s⁻¹ at 150° C. The torque M resulting fromthe force of tangential stretching of the sample between the rotatingdrums F was recorded by the rotational rheometer:

M(t)=2RF(t)  (A)

where the radius of drums R=5.155 mm. The Hencky strain rate {dot over(ε)}_(H) at constant drum rotating speed Ω is

$\begin{matrix}{{\overset{.}{ɛ}}_{H} = \frac{2\Omega\; R}{L}} & (B)\end{matrix}$

where the length of the stretching zone between the rotating drumsL=12.72 mm. The transient extensional viscosity η_(E)*(t) was obtainedfor given Hencky strain rate as

$\begin{matrix}{{\eta_{E}^{+}(t)} = {\frac{\sigma_{E}(t)}{{\overset{.}{ɛ}}_{E}} = \frac{F(t)}{{A\left( {t,T} \right)}{\overset{.}{ɛ}}_{E}}}} & (C)\end{matrix}$

where A(t,T) is the cross-sectional area of the sample which thermallyexpands upon melting and exponentially decreases with stretching:

$\begin{matrix}{{A\left( {t,T} \right)} = {A_{o}\mspace{14mu}{\exp\left( {{- {\overset{.}{ɛ}}_{E}}t} \right)}\left( \frac{\rho_{s}}{\rho(T)} \right)^{2\text{/}3}}} & (D)\end{matrix}$

where A₀ and ρ_(s) are the initial cross-sectional area and the densityof the sample measured at room temperature in solid state. The meltdensity ρ(T) is given by ρ(T)=ρ₀−Δρ(T−273.15)T. Therefore, the transientextensional viscosity η_(E)*(t) as a function of time was calculated ateach extension rate as

$\begin{matrix}{{\eta_{E}^{+}(t)} = {\frac{M - M_{offset}}{2R{\overset{.}{ɛ}}_{E}A_{0}\mspace{14mu}{\exp\left( {{- {\overset{.}{ɛ}}_{E}}t} \right)}}\left( \frac{\rho(T)}{\rho_{s}} \right)^{2\text{/}3}}} & (E)\end{matrix}$

where M_(offset) is a pre-set torque which can be applied prior to theactual test. To compare the extensional response to the linearviscoelastic (LVE) limit, the LVE envelop 3η⁺(t) was obtained from therelaxation spectrum of the dynamic frequency sweep data measured at 150°C. as

$\begin{matrix}{{\eta^{+}(t)} = {\sum\limits_{i = 1}^{N}\;{G_{i}{\lambda_{i}\left\lbrack {1 - {\exp\left( {{- t}\text{/}\lambda_{i}} \right)}} \right\rbrack}}}} & (F)\end{matrix}$

where the set of G_(i) and λ_(i) define the relaxation spectrum of thematerial.

In general, it has been observed that when long chain branching existsin the polymer, the transient extensional viscosity deviates from theLVE drastically by increasing slope just before breakage. This behavioris called the strain hardening. In contrast, for linear resins thetransient extensional viscosity growth curves show no strain hardeningby continuing to follow the LVE envelop (3η⁺(t)) according to theTrouton's rule.

Metals content, such as the amount of catalyst residue in the ethylenepolymer or the article of manufacture (on a ppm basis), can bedetermined by ICP analysis on a PerkinElmer Optima 8300 instrument.Polymer samples can be ashed in a Thermolyne furnace with sulfuric acidovernight, followed by acid digestion in a HotBlock with HCl and HNO₃(3:1 v:v).

Fluorided silica-coated alumina activator-supports (FSCA) used inExamples 1-2 were prepared as follows. Bohemite was obtained from W.R.Grace & Company under the designation “Alumina A” and having a surfacearea of 300 m²/g, a pore volume of 1.3 mL/g, and an average particlesize of 100 microns. The alumina was first calcined in dry air at about600° C. for approximately 6 hours, cooled to ambient temperature, andthen contacted with tetraethylorthosilicate in isopropanol to equal 25wt. % SiO₂. After drying, the silica-coated alumina was calcined at 600°C. for 3 hours. Fluorided silica-coated alumina (7 wt. % F) was preparedby impregnating the calcined silica-coated alumina with an ammoniumbifluoride solution in methanol, drying, and then calcining for 3 hoursat 600° C. in dry air. Afterward, the fluorided silica-coated alumina(FSCA) was collected and stored under dry nitrogen, and was used withoutexposure to the atmosphere.

Pilot plant polymerizations were conducted in a 30-gallon slurry loopreactor at a production rate of approximately 30 pounds of polymer perhour. Polymerization runs were carried out under continuous particleform process conditions in a loop reactor (also referred to as a slurryprocess) by contacting separate metallocene solutions, an organoaluminumsolution (triisobutylaluminum, TIBA), and an activator-support(fluorided silica-coated alumina, FSCA) in a 1-L stirred autoclave (30min residence time) with output to the loop reactor.

Ethylene used was polymerization grade ethylene which was purifiedthrough a column of AZ 300 (activated at 300-500° F. in nitrogen).1-Hexene was polymerization grade 1-hexene (obtained from ChevronPhillips Chemical Company) which was purified by nitrogen purging andstorage over AZ 300 activated at 300-500° F. in nitrogen. Liquidisobutane was used as the diluent.

Certain polymerization conditions for Examples 1-2 are provided in TableI below (mole % ethylene and ppm by weight of triisobutylaluminum (TIBA)are based on isobutane diluent). The polymerization conditions alsoincluded a reactor pressure of 590 psig, a polymerization temperature of97° C., a feed rate of 30 lb/hr ethylene, and 2.5-3.5 ppm total of MET 1and MET 2 (based on the weight of isobutane diluent). The structures forMET 1 and MET 2, used in Examples 1-2, are shown below:

TABLE I 1-Hexene H₂ Weight ratio C₂H₄ TIBA Example (lb/hr) (lb/hr) MET1/MET 2 mole % ppm 1 0.16 0.0021 1.88 11.73 143 2 0.15 0.0020 2.01 12.22144

Blow molded 1-gallon containers were produced under suitable conditionson a Uniloy reciprocating blow molding machine. The parison was extrudedusing a 2.5″ diverging die and then blown into a mold to produce the1-gallon containers weighing approximately 105 g at the following set ofprocess controls: 360° F. extruder temperature; 2.1-2.2 shot size; 160 gtotal parison weight; 45 rpm screw speed; 200 (±15) psig back pressure.Drop impact testing was performed on the 1-gallon containers that wereblow molded from the polymers of Examples 1-3, generally in accordancewith ASTM D2463.

Examples 1-4

Comparative Example 3 was a commercially-available chromium-catalyzedethylene/1-hexene copolymer resin from Chevron-Phillips Chemical CompanyLP, and Comparative Example 4 was a linear dual-metallocene blow moldingresin (with no long chain branching).

For the polymers of Examples 1-3, Table II summarizes various molecularweight, LCB (Janzen-Colby), rheology, melt index, density, ESCR, andblow molded bottle properties, while Table III summarizes an extrusionand blow molding processing comparison, and FIG. 1 illustrates themolecular weight distribution curves (amount of polymer versus thelogarithm of molecular weight) for the polymers of Examples 1-3. Ascompared to chromium-based Example 3, the ethylene/1-hexene copolymersof Examples 1-2 had less LCBs per million total carbon atoms (viaJanzen-Colby), lower relaxations times, higher CY-a parameters, andsignificantly better ESCR properties.

Using the chromium polymer of Example 3 as a benchmark, Table III showsthat the polymers of Examples 1-2 had unexpectedly lower extrusionpressure (psi) and equivalent part weights, cycle times, layflats, andoutput rates (measured at 100 rpm with a 0.022″ die gap). The processingsimilarities are also shown by the relatively small rheology differencesbetween Examples 2-3 and Comparative Example 1 in FIG. 10.

FIG. 2 illustrates the short chain branch distributions for the polymersof Examples 1-2. Surprisingly, these polymers have a substantially flatSCBD, in which the SCB content is generally constant with increasingmolecular weight.

FIG. 3 illustrates a plot of the molecular weight distribution and longchain branch distribution of the polymer of Example 1, while FIG. 4illustrates a plot of the molecular weight distribution and long chainbranch distribution of the polymer of Example 2. The concentration oflong chain branch content in the ˜300,000-900,000 g/mol molecular weightrange (but not in the very high molecular weight fraction) of theinventive polymers of Examples 1-2 is illustrated in these figures.Further, FIG. 5 illustrates a plot of the radius of gyration versus themolecular weight for a linear standard and the polymers of Examples 1-2,and demonstrates the deviation of the polymers of Examples 1-2 from thelinear standard, due to the presence of LCB in the ˜300,000-900,000g/mol range. From FIGS. 3-4, Table IV summarizes the LCB content of therespective ethylene polymers in certain molecular weight ranges.

As an example, the number-average number of LCBs per 1,000,000 totalcarbon atoms of the respective polymers in FIGS. 3-4 in the molecularweight range of 300,000 to 900,000 g/mol and in the molecular weightrange of 1,000,000 to 2,000,000 g/mol can be calculated based onEquations I and II, respectively, and are summarized in Table IV.

$\begin{matrix}{\overset{\_}{\lambda} = \frac{\sum\limits_{{MW} = {300\mspace{14mu}{kg}\text{/}{mol}}}^{{MW} = {900\mspace{14mu}{kg}\text{/}{mol}}}\;{{\lambda_{i}\left( \frac{dw}{d\left( {{Log}\mspace{14mu} M} \right)} \right)}_{i}\left( {d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}}}{\sum\limits_{{MW} = {300\mspace{14mu}{kg}\text{/}{mol}}}^{{MW} = {900\mspace{14mu}{kg}\text{/}{mol}}}\;{\left( \frac{dw}{d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}\left( {d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}}}} & {{Equation}\mspace{14mu} I} \\{\overset{\_}{\lambda} = \frac{\sum\limits_{{MW} = {1000\mspace{14mu}{kg}\text{/}{mol}}}^{{MW} = {2000\mspace{14mu}{kg}\text{/}{mol}}}\;{{\lambda_{i}\left( \frac{dw}{d\left( {{Log}\mspace{14mu} M} \right)} \right)}_{i}\left( {d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}}}{\sum\limits_{{MW} = {1000\mspace{14mu}{kg}\text{/}{mol}}}^{{MW} = {2000\mspace{14mu}{kg}\text{/}{mol}}}\;{\left( \frac{dw}{d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}\left( {d\left( {{Log}\mspace{14mu} M} \right)} \right)_{i}}}} & {{Equation}\mspace{14mu}{II}}\end{matrix}$

where {tilde over (λ)} is the number-average LCB number in therespective molecular weight range and λ_(i) is LCB at slice i. As shownin Table IV, the number-average number of LCBs per 1,000,000 totalcarbon atoms of the polymers in FIGS. 3-4 in the molecular weight rangeof 300,000 to 900,000 g/mol (or 400,000 to 600,000 g/mol) issignificantly—and unexpectedly—greater than that in the molecular weightrange of 1,000,000 to 2,000,000 g/mol.

FIGS. 6-8 illustrates extensional viscosity plots, respectively, for thepolymers of Example 1, Example 2, and Comparative Example 4. Extensionalrheology was used as a means to quantify the amount of LCBs, since for aNewtonian fluid, the ratio of extensional viscosity will be equal to 3times the shear viscosity; the ratio of η_(E)/3η will be equal to 1 fora Newtonian fluid (see the linear polymer of Comparative Example 4 inFIG. 8, with no long chain branching). For molten polymers with strainhardening due to the presence of LCBs, the ratio of η_(E)/3η will begreater than 1. FIGS. 6-7 are extensional viscosity plots at for thepolymers of Examples 1-2, determined using SER. The minor scatter in thebaseline was due to the limited amount of samples for the SERexperiments. From FIGS. 6-7, FIG. 9 was prepared to summarize themaximum ratio of η_(E)/3η at extensional rates in the 0.03 to 10 sec⁻¹range for the polymers of Examples 1-2. A higher ratio equates to morestrain hardening, and therefore, higher levels of LCBs. For theseinventive polymers, unexpectedly, the maximum ratio of η_(E)/3η at theextensional rate of 0.03 sec⁻¹ ranged from 3 to 4, and ranged from 1.5to 2.5 at an extensional rate of 0.1 sec⁻¹.

While not wishing to be bound by theory, higher levels of LCB—and thushigher extensional viscosity—can be obtained herein by decreasing theconcentration of ethylene in the reactor. Additionally or alternatively,increasing comonomer levels (e.g., more 1-hexene) for a given ethyleneconcentration (the ratio of [1-hexene]/[ethylene]) can be used toincrease levels of LCB in the polymer. Levels of LCB also can beadjusted by varying the ratio of the metallocene compounds in thecatalyst system.

Thus, the ethylene copolymers disclosed herein offer a beneficialcombination of density, melt flow, molecular weight, relaxation time,long chain branching, and extensional rheology properties, resulting inprocessability comparable to chromium-based polymers, but with improvedESCR and toughness properties.

TABLE II Mn/1000 Mw/1000 Mz/1000 Mp/1000 LCB/million Example (g/mol)(g/mol) (g/mol) (g/mol) Mw/Mn Mz/Mw carbon atoms 1 18.3 156 783 40.28.52 5.02 8.2 2 18.7 149 740 44.5 8.03 4.97 10.9 3 20.7 134 635 52.56.47 4.74 37 η₀ τ_(η) η @ 0.1 sec η @ 100 sec η @ 0.1/ η @ HLMI Example(Pa-sec) (sec) CY-a (Pa-sec) (Pa-sec) η @ 100 (Pa-sec) 1 1.02E+05 1.20.31 33710 1181 28.5 367 2 1.40E+05 1.4 0.26 32780 1165 28.1 401 31.43E+06 3.7 0.14 35480 1318 26.9 757 Bent Strip Yield Bottle BottleBottle Drop HLMI MI Density ESCR Strength ESCR Topload Impact Example(g/10 min) (g/10 min) (g/cc) (hr) (psi) (hr) (lb) (ft) 1 45 0.30 0.9583115 4260 499 175 >12 2 50 0.36 0.9581 79 4310 — — — 3 32 0.33 0.9556 <504130 165 175 11.9

TABLE III Melt Weight Die Parison Part Screw Cycle Head Top Bottom MeltTemp. Setting Gap Weight Weight Charge Time Pressure Layflat LayflatOutput Strength Example (° F.) (%) (in) (g) (g) (sec) (sec) (psi) (in)(in) (g/min) (sec) 1 411 1.2 0.015 160.8 105.5 15.3 17.0 4450 5.52 5.791295 14.3 2 405 0 0.013 161.5 109.6 15.2 16.9 4600 5.46 5.70 1297 14.7 3416 1.2 0.015 160.2 105.1 14.6 16.3 5040 5.22 5.55 1302 31.5

TABLE IV Average LCBs per 1,000,000 Example Example total carbon atoms 12 (a) 300,000-900,000 g/mol range 7.83 6.66 (b) 1,000,000-2,000,00 g/molrange 1.89 2.45 Percentage (a)/(b) 414% 272% (a) 400,000-600,000 g/molrange 8.98 8.32 (b) 1,000,000-2,000,000 g/mol range 1.89 2.45 Percentage(a)/(b) 475% 340%

The invention is described above with reference to numerous aspects andspecific examples. Many variations will suggest themselves to thoseskilled in the art in light of the above detailed description. All suchobvious variations are within the full intended scope of the appendedclaims. Other aspects of the invention can include, but are not limitedto, the following (aspects are described as “comprising” but,alternatively, can “consist essentially of” or “consist of”):

Aspect 1. An ethylene polymer having:

a melt index of less than or equal to about 1 g/10 min;

a density in a range from about 0.94 to about 0.965 g/cm³;

a Mw in a range from about 100,000 to about 250,000 g/mol;

a relaxation time from about 0.5 to about 3 sec; and

an average number of long chain branches (LCBs) per 1,000,000 totalcarbon atoms of the polymer in a molecular weight range of 300,000 to900,000 g/mol that is greater (by any amount disclosed herein, e.g., atleast 50%, at least 75%, at least 100%, at least 150%, at least 200%,etc.) than that in a molecular weight range of 1,000,000 to 2,000,000g/mol.

Aspect 2. An ethylene polymer having:

a melt index of less than or equal to about 1 g/10 min;

a density in a range from about 0.94 to about 0.965 g/cm³;

a Mw in a range from about 100,000 to about 250,000 g/mol;

a relaxation time from about 0.5 to about 3 sec;

an average number of long chain branches (LCBs) per 1,000,000 totalcarbon atoms of the polymer in a molecular weight range of 1,000,000 to2,000,000 g/mol of less than or equal to about 5; and

a maximum ratio of >E/3η at an extensional rate of 0.1 sec⁻¹ in a rangefrom about 1.2 to about 10.

Aspect 3. The polymer defined in aspect 1 or 2, wherein the ethylenepolymer has a melt index (MI) in any range disclosed herein, e.g., lessthan or equal to about 0.7 g/10 nm, less than or equal to about 0.5 g/10min, from about 0.1 to about 0.5 g/10 min, from about 0.2 to about 0.4g/10 min, etc.

Aspect 4. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a high load melt index (HLMI) in anyrange disclosed herein, e.g., from about 10 to about 65 g/10 min, fromabout 35 to about 55 g/10 min, from about 20 to about 60 g/10 min, fromabout 40 to about 55 g/10 min, etc.

Aspect 5. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a ratio of HLMI/MI in any rangedisclosed herein, e.g., from about 100 to about 200, from about 120 toabout 170, from about 130 to about 160, etc.

Aspect 6. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a density in any range disclosedherein, e.g., from about 0.942 to about 0.965 g/cm³, from about 0.94 toabout 0.96 g/cm³, from about 0.95 to about 0.965 g/cm³, from about 0.955to about 0.962 g/cm³, from about 0.955 to about 0.96 g/cm³, etc.

Aspect 7. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a ratio of Mw/Mn in any range disclosedherein, e.g., from about 5 to about 15, from about 6 to about 12, fromabout 6 to about 10, from about 7 to about 10, etc.

Aspect 8. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a ratio of Mz/Mw in any range disclosedherein, e.g., from about 3.5 to about 10, from about 4 to about 8, fromabout 4 to about 6, from about 4.5 to about 5.5, etc.

Aspect 9. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a Mz in any range disclosed herein,e.g., from about 500,000 to about 2,000,000 g/mol, from about 600,000 toabout 1,200,000 g/mol, from about 650,000 to about 1,000,000 g/mol, fromabout 700,000 to about 900,000 g/mol, etc.

Aspect 10. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a Mw in any range disclosed herein,e.g., from about 125,000 to about 250,000 g/mol, from about 100,000 toabout 200,000 g/mol, from about 110,000 to about 190,000 g/mol, fromabout 125,000 to about 175,000 g/mol, etc.

Aspect 11. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a Mn in any range disclosed herein,e.g., from about 10,000 to about 30,000 g/mol, from about 10,000 toabout 25,000 g/mol, from about 15,000 to about 25,000 g/mol, from about15,000 to about 20,000 g/mol, etc.

Aspect 12. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has an average number of long chainbranches (LCBs) per 1,000,000 total carbon atoms of the polymer in amolecular weight range of 300,000 to 900,000 g/mol in any rangedisclosed herein, e.g., from 3 to about to 15, from about 4 to about 10,from about 5 to about 9, from about 6 to about 8, etc.

Aspect 13. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has an average number of long chainbranches (LCBs) per 1,000,000 total carbon atoms of the polymer in amolecular weight range of 400,000 to 600,000 g/mol in any rangedisclosed herein, e.g., from 4 to about 15, from about 5 to about 12,from about 7 to about 10, from about 8 to about 9, etc.

Aspect 14. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has an average number of long chainbranches (LCBs) per 1,000,000 total carbon atoms of the polymer in amolecular weight range of 1,000,000 to 2,000,000 g/mol in any rangedisclosed herein, e.g., less than or equal to about 5, less than orequal to about 4, less than or equal to about 3.5, less than or equal toabout 3, etc.

Aspect 15. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer contains from about 5 to about 15 LCBs,from about 6 to about 14 LCBs, from about 8 to about 12 LCBs, etc., per1,000,000 total carbon atoms.

Aspect 16. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a maximum ratio of η_(E)/3η at anextensional rate of 0.1 sec⁻¹ in any range disclosed herein, e.g., fromabout 1.2 to about 10, from about 1.5 to about 8, from about 1.5 toabout 5, from about 1.2 to about 4, from about 1.2 to about 3, fromabout 1.4 to about 3.5, from about 1.4 to about 3, from about 1.5 toabout 2.5, etc.

Aspect 17. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a maximum ratio of η_(E)/3η at anextensional rate of 0.03 sec⁻¹ in any range disclosed herein, e.g., fromabout 1.2 to about 10, from about 1.5 to about 8, from about 2 to about7, from about 2 to about 5, from about 2.5 to about 4.5, from about 3 toabout 4, etc.

Aspect 18. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a CY-a parameter in any range disclosedherein, e.g., from about 0.15 to about 0.45, from about 0.2 to about0.4, from about 0.22 to about 0.35, from about 0.22 to about 0.32, etc.

Aspect 19. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a zero-shear viscosity in any rangedisclosed herein, e.g., from about 1×10³ to about 1×10⁸ Pa-sec, fromabout 1×10⁴ to about 1×10⁷ Pa-sec, from about 1×10⁴ to about 1×10⁶Pa-sec, etc.

Aspect 20. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a relaxation time in any rangedisclosed herein, e.g., from about 0.75 to about 2.5 sec, from about 1to about 2 sec, from about 1 to about 1.5 sec, etc.

Aspect 21. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a viscosity at 100 sec⁻¹ (eta @ 100 orη@ 100) in any range disclosed herein, e.g., from about 750 to about1750, from about 850 to about 1300, from about 1000 to about 1500, fromabout 1000 to about 1300 Pa-sec, etc.

Aspect 22. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a viscosity at HLMI (eta @ HLMI or η@HLMI) in any range disclosed herein, e.g., from about 300 to about 750,from about 300 to about 500, from about 300 to about 450, from about 350to about 450 Pa-sec, etc.

Aspect 23. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a ratio of η@ 0.1/η@ 100 in any rangedisclosed herein, e.g., from about 20 to about 45, from about 20 toabout 35, from about 22 to about 32, from about 25 to about 30, etc.

Aspect 24. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a substantially constant number ofshort chain branches (SCBs) per 1000 total carbon atoms, or asubstantially flat SCBD (short chain branching distribution).

Aspect 25. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a part weight in any range disclosedherein, e.g., from about 95 to about 115, from about 100 to about 115,from about 95 to about 110, from about 100 to about 110 g, etc.

Aspect 26. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a layflat (top) in any range disclosedherein, e.g., from about 5.2 to about 6, from about 5 to about 5.7, fromabout 5.2 to about 5.7 inches, etc.

Aspect 27. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a cycle time in any range disclosedherein, e.g., from about 13 to about 20, from about 14 to about 19, fromabout 15 to about 18, from about 16 to about 17 seconds, etc.

Aspect 28. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has an environmental stress crackresistance (ESCR—bottle in 10% Igepal, 140° F., ASTM D2561) in any rangedisclosed herein, e.g., at least 200 hours, at least 250 hours, at least300 hours, at least 400 hours, at least 500 hours, etc.

Aspect 29. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has an environmental stress crackresistance (ESCR—bent strip in 10% Igepal, 50° C., 75 mils, ASTM D1693)in any range disclosed herein, e.g., at least 50 hours, at least 60hours, at least 75 hours, at least 85 hours, at least 100 hours, etc.

Aspect 30. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer contains, independently, less than 0.1 ppm(by weight), less than 0.08 ppm, less than 0.05 ppm, less than 0.03 ppm,etc., of chromium and titanium.

Aspect 31. The polymer defined in any one of the preceding aspects,wherein the polymer further comprises any additive disclosed herein,e.g., an antioxidant, an acid scavenger, an antiblock additive, a slipadditive, a colorant, a filler, a polymer processing aid, a UV additive,etc., or combinations thereof.

Aspect 32. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer has a bimodal molecular weightdistribution.

Aspect 33. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer is a single reactor product, e.g., not apost-reactor blend of two polymers, for instance, having differentmolecular weight characteristics.

Aspect 34. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer comprises an ethylene/α-olefin copolymerand/or an ethylene homopolymer.

Aspect 35. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer comprises an ethylene/1-butene copolymer,an ethylene/1-hexene copolymer, an ethylene/1-octene copolymer, anethylene homopolymer, or any combination thereof.

Aspect 36. The polymer defined in any one of the preceding aspects,wherein the ethylene polymer comprises an ethylene/1-hexene copolymer.

Aspect 37. An article (e.g., a blow molded product) comprising theethylene polymer defined in any one of aspects 1-36.

Aspect 38. An article comprising the ethylene polymer defined in any oneof aspects 1-36, wherein the article is an agricultural film, anautomobile part, a bottle, a container for chemicals, a drum, a fiber orfabric, a food packaging film or container, a food service article, afuel tank, a geomembrane, a household container, a liner, a moldedproduct, a medical device or material, an outdoor storage product,outdoor play equipment, a pipe, a sheet or tape, a toy, or a trafficbarrier.

Aspect 39. A catalyst composition comprising:

catalyst component I comprising any single atom bridged or two atombridged metallocene compound disclosed herein with two indenyl groups;

catalyst component II comprising any single atom bridged metallocenecompound disclosed herein with a fluorenyl group and a cyclopentadienylgroup, and with an alkenyl substituent on the single atom bridge and/oron the cyclopentadienyl group;

any activator disclosed herein; and

optionally, any co-catalyst disclosed herein.

Aspect 40. The composition defined in aspect 39, wherein the activatorcomprises an activator-support, an aluminoxane compound, an organoboronor organoborate compound, an ionizing ionic compound, or any combinationthereof.

Aspect 41. The composition defined in aspect 39, wherein the activatorcomprises an aluminoxane compound.

Aspect 42. The composition defined in aspect 39, wherein the activatorcomprises an organoboron or organoborate compound.

Aspect 43. The composition defined in aspect 39, wherein the activatorcomprises an ionizing ionic compound.

Aspect 44. The composition defined in aspect 39, wherein the activatorcomprises an activator-support, the activator-support comprising anysolid oxide treated with any electron-withdrawing anion disclosedherein.

Aspect 45. The composition defined in aspect 39, wherein the activatorcomprises fluorided alumina, chlorided alumina, bromided alumina,sulfated alumina, fluorided silica-alumina, chlorided silica-alumina,bromided silica-alumina, sulfated silica-alumina, fluoridedsilica-zirconia, chlorided silica-zirconia, bromided silica-zirconia,sulfated silica-zirconia, fluorided silica-titania, fluoridedsilica-coated alumina, fluorided-chlorided silica-coated alumina,sulfated silica-coated alumina, phosphated silica-coated alumina, or anycombination thereof.

Aspect 46. The composition defined in aspect 39, wherein the activatorcomprises fluorided alumina, sulfated alumina, fluorided silica-alumina,sulfated silica-alumina, fluorided silica-coated alumina,fluorided-chlorided silica-coated alumina, sulfated silica-coatedalumina, or any combination thereof.

Aspect 47. The composition defined in aspect 39, wherein the activatorcomprises a fluorided solid oxide and/or a sulfated solid oxide.

Aspect 48. The composition defined in any one of aspects 44-47, whereinthe activator further comprises any metal or metal ion disclosed herein,e.g., zinc, nickel, vanadium, titanium, silver, copper, gallium, tin,tungsten, molybdenum, zirconium, or any combination thereof.

Aspect 49. The composition defined in any one of aspects 39-48, whereinthe catalyst composition comprises a co-catalyst, e.g., any suitableco-catalyst.

Aspect 50. The composition defined in any one of aspects 39-49, whereinthe co-catalyst comprises any organoaluminum compound disclosed herein.

Aspect 51. The composition defined in aspect 50, wherein theorganoaluminum compound comprises trimethylaluminum, triethylaluminum,triisobutylaluminum, or a combination thereof.

Aspect 52. The composition defined in any one of aspects 44-51, whereinthe catalyst composition comprises catalyst component I, catalystcomponent II, a solid oxide treated with an electron-withdrawing anion,and an organoaluminum compound.

Aspect 53. The composition defined in any one of aspects 39-52, whereincatalyst component I has two unsubstituted indenyl groups.

Aspect 54. The composition defined in any one of aspects 39-53, whereincatalyst component I has a single carbon or silicon bridging atom.

Aspect 55. The composition defined in aspect 54, wherein the carbon orsilicon bridging atom has two substituents independently selected from Hor a C₁ to C₁₈ hydrocarbyl group, e.g., a C₁ to C₆ alkyl group.

Aspect 56. The composition defined in any one of aspects 39-53, whereincatalyst component I has a two carbon atom bridge.

Aspect 57. The composition defined in any one of aspects 39-52, whereinat least one indenyl group is substituted.

Aspect 58. The composition defined in aspect 57, wherein catalystcomponent I has a single carbon or silicon bridging atom.

Aspect 59. The composition defined in aspect 58, wherein the carbon orsilicon bridging atom has two substituents independently selected from Hor a C₁ to C₁₈ hydrocarbyl group, e.g., a C₁ to C₆ alkyl group.

Aspect 60. The composition defined in any one of aspects 57-59, whereinany substituent on an indenyl group is independently selected from H ora C₁ to C₁₈ hydrocarbyl group, e.g., a C₁ to C₆ alkyl group.

Aspect 61. The composition defined in any one of aspects 39-60, whereincatalyst component I contains zirconium.

Aspect 62. The composition defined in any one of aspects 39-61, whereincatalyst component II has a single carbon or silicon bridging atom.

Aspect 63. The composition defined in aspect 62, wherein the carbon orsilicon bridging atom has two substituents independently selected from Hor a C₁ to C₁₈ hydrocarbyl group, e.g., a phenyl group.

Aspect 64. The composition defined in any one of aspects 39-63, whereinthe fluorenyl group is substituted.

Aspect 65. The composition defined in any one of aspects 39-64, whereinthe alkenyl substituent is a C₃ to C₁₈ alkenyl group, e.g., a C₃ to C₈terminal alkenyl group.

Aspect 66. The composition defined in any one of aspects 39-65, whereincatalyst component II contains zirconium or hafnium.

Aspect 67. The composition defined in any one of aspects 44-66, whereinthe catalyst composition is substantially free of aluminoxane compounds,organoboron or organoborate compounds, ionizing ionic compounds, orcombinations thereof.

Aspect 68. The composition defined in any one of aspects 39-67, whereina weight ratio of catalyst component I to catalyst component II in thecatalyst composition is in any range disclosed herein, e.g., from about10:1 to about 1:10, from about 5:1 to about 1:5, from about 1.2:1 toabout 5:1, from about 1.5:1 to about 4:1, from about 1.5:1 to about2.5:1, etc.

Aspect 69. The composition defined in any one of aspects 39-68, whereinthe catalyst composition is produced by a process comprising contacting,in any order, catalyst component I, catalyst component II, and theactivator.

Aspect 70. The composition defined in any one of aspects 39-68, whereinthe catalyst composition is produced by a process comprising contacting,in any order, catalyst component I, catalyst component II, theactivator, and the co-catalyst.

Aspect 71. The composition defined in any one of aspects 39-70, whereina catalyst activity of the catalyst composition is in any rangedisclosed herein, e.g., from about 500 to about 5000, from about 750 toabout 4000, from about 1000 to about 3500 grams, etc., of ethylenepolymer per gram of activator-support per hour, under slurrypolymerization conditions, with a triisobutylaluminum co-catalyst, usingisobutane as a diluent, and with a polymerization temperature of 95° C.and a reactor pressure of 590 psig.

Aspect 72. An olefin polymerization process, the process comprisingcontacting the catalyst composition defined in any one of aspects 39-71with an olefin monomer and an optional olefin comonomer in apolymerization reactor system under polymerization conditions to producean olefin polymer.

Aspect 73. The process defined in aspect 72, wherein the olefin monomercomprises any olefin monomer disclosed herein, e.g., any C₂-C₂₀ olefin.

Aspect 74. The process defined in aspect 72 or 73, wherein the olefinmonomer and the olefin comonomer independently comprise a C₂-C₂₀alpha-olefin.

Aspect 75. The process defined in any one of aspects 72-74, wherein theolefin monomer comprises ethylene.

Aspect 76. The process defined in any one of aspects 72-75, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising a C₃-C₁₀ alpha-olefin.

Aspect 77. The process defined in any one of aspects 72-76, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.

Aspect 78. The process defined in any one of aspects 72-74, wherein theolefin monomer comprises propylene.

Aspect 79. The process defined in any one of aspects 72-78, wherein thepolymerization reactor system comprises a batch reactor, a slurryreactor, a gas-phase reactor, a solution reactor, a high pressurereactor, a tubular reactor, an autoclave reactor, or a combinationthereof.

Aspect 80. The process defined in any one of aspects 72-79, wherein thepolymerization reactor system comprises a slurry reactor, a gas-phasereactor, a solution reactor, or a combination thereof.

Aspect 81. The process defined in any one of aspects 72-80, wherein thepolymerization reactor system comprises a loop slurry reactor.

Aspect 82. The process defined in any one of aspects 72-81, wherein thepolymerization reactor system comprises a single reactor.

Aspect 83. The process defined in any one of aspects 72-81, wherein thepolymerization reactor system comprises 2 reactors.

Aspect 84. The process defined in any one of aspects 72-81, wherein thepolymerization reactor system comprises more than 2 reactors.

Aspect 85. The process defined in any one of aspects 72-84, wherein theolefin polymer comprises any olefin polymer disclosed herein.

Aspect 86. The process defined in any one of aspects 72-77 and 79-85,wherein the olefin polymer comprises an ethylene homopolymer, anethylene/1-butene copolymer, an ethylene/1-hexene copolymer, and/or anethylene/1-octene copolymer.

Aspect 87. The process defined in any one of aspects 72-77 and 79-85,wherein the olefin polymer comprises an ethylene/1-hexene copolymer.

Aspect 88. The process defined in any one of aspects 72-74 and 78-85,wherein the olefin polymer comprises a polypropylene homopolymer or apropylene-based copolymer.

Aspect 89. The process defined in any one of aspects 72-88, wherein thepolymerization conditions comprise a polymerization reaction temperaturein a range from about 60° C. to about 120° C. and a reaction pressure ina range from about 200 to about 1000 psig (about 1.4 to about 6.9 MPa).

Aspect 90. The process defined in any one of aspects 72-89, wherein thepolymerization conditions are substantially constant, e.g., for aparticular polymer grade.

Aspect 91. The process defined in any one of aspects 72-90, wherein nohydrogen is added to the polymerization reactor system.

Aspect 92. The process defined in any one of aspects 72-90, whereinhydrogen is added to the polymerization reactor system.

Aspect 93. The process defined in any one of aspects 72-92, wherein theolefin polymer produced is defined in any one of aspects 1-36.

Aspect 94. An olefin polymer produced by the olefin polymerizationprocess defined in any one of aspects 72-92.

Aspect 95. An ethylene polymer defined in any one of aspects 1-36produced by the process defined in any one of aspects 72-92.

Aspect 96. An article comprising the polymer defined in any one ofaspects 94-95.

Aspect 97. A method or forming or preparing an article of manufacturecomprising an olefin polymer, the method comprising (i) performing theolefin polymerization process defined in any one of aspects 72-92 toproduce an olefin polymer (e.g., the ethylene polymer of any one ofaspects 1-36), and (ii) forming the article of manufacture comprisingthe olefin polymer, e.g., via any technique disclosed herein.

1-20. (canceled)
 21. An ethylene polymer having: a melt index of lessthan or equal to about 0.7 g/10 min; a density in a range from about0.942 to about 0.965 g/cm³; a Mw in a range from about 110,000 to about190,000 g/mol; a relaxation time from about 0.75 to about 2.5 sec; andan average number of long chain branches (LCBs) per 1,000,000 totalcarbon atoms of the ethylene polymer in a molecular weight range of300,000 to 900,000 g/mol that is at least 50% greater than that in amolecular weight range of 1,000,000 to 2,000,000 g/mol.
 22. An articleof manufacture comprising the ethylene polymer of claim
 21. 23. Theethylene polymer of claim 21, wherein the ethylene polymer comprises anethylene/1-butene copolymer, an ethylene/1-hexene copolymer, anethylene/1-octene copolymer, or a combination thereof.
 24. The ethylenepolymer of claim 23, wherein the ethylene polymer has: a ratio of Mw/Mnin a range from about 6 to about 10; and a ratio of Mz/Mw in a rangefrom about 4 to about
 6. 25. The ethylene polymer of claim 23, whereinthe ethylene polymer has: a CY-a parameter in a range from about 0.2 toabout 0.4; and an environmental stress crack resistance (ESCR, ASTMD1693) of at least 60 hours.
 26. The ethylene polymer of claim 21,wherein: the melt index is in a range from about 0.1 to about 0.5 g/10min; the density is in a range from about 0.95 to about 0.965 g/cm³; theaverage number of LCBs per 1,000,000 total carbon atoms of the ethylenepolymer in the molecular weight range of 300,000 to 900,000 g/mol is atleast 100% greater than that in the molecular weight range of 1,000,000to 2,000,000 g/mol; and the ethylene polymer comprises anethylene/1-butene copolymer, an ethylene/1-hexene copolymer, anethylene/1-octene copolymer, or a combination thereof.
 27. A blow moldedproduct comprising the ethylene polymer of claim
 26. 28. The ethylenepolymer of claim 26, wherein the ethylene polymer has: an average numberof from about 5 to about 9 LCBs per 1,000,000 total carbon atoms of theethylene polymer in the molecular weight range of 300,000 to 900,000g/mol; and an average number of from about 7 to about 10 LCBs per1,000,000 total carbon atoms of the ethylene polymer in a molecularweight range of 400,000 to 600,000 g/mol.
 29. An ethylene polymerhaving: a melt index of less than or equal to about 0.7 g/10 min; adensity in a range from about 0.94 to about 0.965 g/cm³; a Mw in a rangefrom about 100,000 to about 200,000 g/mol; a relaxation time from about0.5 to about 3 sec; an average number of long chain branches (LCBs) per1,000,000 total carbon atoms of the ethylene polymer in a molecularweight range of 1,000,000 to 2,000,000 g/mol of less than or equal toabout 4; and a maximum ratio of extensional viscosity to three timesshear viscosity (η_(E)/3η) at an extensional rate of 0.1 sec⁻¹ in arange from about 1.2 to about
 10. 30. An article of manufacturecomprising the ethylene polymer of claim
 29. 31. The ethylene polymer ofclaim 29, wherein the ethylene polymer has: a CY-a parameter in a rangefrom about 0.2 to about 0.4; and an environmental stress crackresistance (ESCR, ASTM D1693) of at least 60 hours.
 32. The ethylenepolymer of claim 29, wherein: the average number of LCBs per 1,000,000total carbon atoms of the ethylene polymer in the molecular weight rangeof 1,000,000 to 2,000,000 g/mol is less than or equal to about 3.5; andthe maximum ratio of η_(E)/3η at the extensional rate of 0.1 sec⁻¹ is ina range from about 1.5 to about
 8. 33. The ethylene polymer of claim 29,wherein: the melt index is in a range from about 0.1 to about 0.5 g/10min; the density is in a range from about 0.95 to about 0.96 g/cm³; theMw is in a range from about 125,000 to about 175,000 g/mol; therelaxation time is in a range from about 0.75 to about 2.5 sec; theaverage number of LCBs per 1,000,000 total carbon atoms of the ethylenepolymer in the molecular weight range of 1,000,000 to 2,000,000 g/mol isless than or equal to about 3; the maximum ratio of η_(E)/3η at theextensional rate of 0.1 sec⁻¹ is in a range from about 1.2 to about 4;and the ethylene polymer comprises an ethylene/1-butene copolymer, anethylene/1-hexene copolymer, an ethylene/1-octene copolymer, or acombination thereof.
 34. The ethylene polymer of claim 33, wherein theethylene polymer contains from about 6 to about 14 LCBs per 1,000,000total carbon atoms.
 35. An olefin polymerization process, the processcomprising contacting a catalyst composition with ethylene and anα-olefin comonomer in a polymerization reactor system underpolymerization conditions to produce an ethylene polymer, wherein: thecatalyst composition comprises: catalyst component I comprising a singleatom bridged or two atom bridged metallocene compound with two indenylgroups; catalyst component II comprising a single atom bridgedmetallocene compound with a fluorenyl group and a cyclopentadienylgroup, and with an alkenyl substituent on the single atom bridge and/oron the cyclopentadienyl group; an activator; and optionally, aco-catalyst; and the ethylene polymer is characterized by: a melt indexof less than or equal to about 1 g/10 min; a density in a range fromabout 0.94 to about 0.965 g/cm³; a Mw in a range from about 100,000 toabout 250,000 g/mol; a relaxation time from about 0.5 to about 3 sec;and an average number of LCBs per 1,000,000 total carbon atoms of theethylene polymer in a molecular weight range of 300,000 to 900,000 g/molthat is at least 50% greater than that in a molecular weight range of1,000,000 to 2,000,000 g/mol.
 36. The process of claim 35, wherein: theactivator comprises a fluorided solid oxide and/or a sulfated solidoxide; the catalyst composition comprises an organoaluminum co-catalyst;and the polymerization reactor system comprises a slurry reactor, agas-phase reactor, a solution reactor, or a combination thereof.
 37. Theprocess of claim 35, wherein the polymerization reactor system comprisesa loop slurry reactor, a fluidized bed reactor, a solution reactor, or acombination thereof.
 38. The process of claim 37, wherein the activatorcomprises an aluminoxane compound.
 39. The process of claim 37, wherein:hydrogen is added to the polymerization reactor system; and the α-olefincomonomer comprises 1-butene, 1-hexene, 1-octene, or a mixture thereof.40. The process of claim 37, wherein: catalyst component I comprises atwo carbon atom bridged zirconium metallocene compound with two indenylgroups; the alkenyl substituent is on the cyclopentadienyl group of thesingle atom bridged metallocene compound; and the single atom bridge isa carbon atom bridge with two aryl group substituents.
 41. The processof claim 37, wherein a weight ratio of catalyst component I to catalystcomponent II in the catalyst composition is in a range from about 1:5 toabout 5:1.